Navigation and tissue capture systems and methods

ABSTRACT

Navigation and tissue capture systems and methods for navigation to and/or capture of selected tissue using the innate electrical activity of the selected tissue and/or other tissue are described. In the context of left atrial appendage closure, the systems and methods can be used to navigate to the left atrial appendage and capture/control the appendage while a closure instrument (suture, clip, ring) is placed over the appendage and tightened down or a closure method (ablation, cryogenic procedures, stapling, etc.) is performed to close the left atrial appendage. The use of innate electrical activity for navigating devices may be used in connection with other tissues and/or areas of the body.

RELATED APPLICATIONS

This application is a U.S. National Stage Application of InternationalApplication No. PCT/US2009/038544, titled NAVIGATION AND TISSUE CAPTURESYSTEMS AND METHODS, filed on Mar. 27, 2009, published in the Englishlanguage on Oct. 1, 2009 as International Publication No. WO 2009/120593A2, which claims the benefit under 35 U.S.C. §119 of U.S. ProvisionalApplication Ser. No. 61/039,993 filed Mar. 27, 2008, entitled TISSUECAPTURE SYSTEMS AND METHODS and of U.S. Provisional Patent ApplicationSer. No. 61/106,735 filed Oct. 20, 2008, entitled TISSUE CAPTURE SYSTEMSAND METHODS and also of U.S. Provisional Patent Application Ser. No.61/150,656, filed on Feb. 6, 2009, entitled NAVIGATION AND TISSUECAPTURE SYSTEMS AND METHODS; each of which is incorporated herein byreference in their entirety.

Navigation and tissue capture systems and methods for navigating toand/or capturing selected tissue within the internal body of a patientusing innate electrical activity of the selected tissue and/or othertissues are described herein.

Atrial fibrillation is a common cardiac rhythm disorder affecting apopulation of approximately 2.5 million patients in the United Statesalone. Atrial fibrillation results from a number of different causes andis characterized by a rapid chaotic heart beat. In addition to the risksassociated with a disordered heart beat, patients with atrialfibrillation also have an increased risk of stroke. It has beenestimated that approximately 75,000-90,000 atrial fibrillation patientsin the United States each year suffer a stroke related to thatcondition. It appears that strokes in these patients result from embolimany of which may originate from the left atrial appendage. Theirregular heart beat causes blood to pool in the left atrial appendage,allowing clots to accumulate over time. From time to time, a clot maydislodge from the left atrial appendage and may enter the cranialcirculation causing a stroke, the coronary circulation causing amyocardial infarction, the peripheral circulation causing limb ischemia,as well as other vascular beds.

Significant efforts have been made to reduce the risk of stroke inpatients suffering from atrial fibrillation. Most commonly, thosepatients are treated with blood thinning agents, such as Coumadin, toreduce the risk of clot formation. While such treatment cansignificantly reduce the risk of stroke, it also increases the risk ofbleeding and for that reason is inappropriate for many atrialfibrillation patients.

As an alternative to drug therapy, minimally invasive surgicalprocedures for closing the left atrial appendage have been proposed.Most commonly, the left atrial appendage has been closed or removedconcurrently with open surgical procedures, typically where the hearthas stopped and the chest opened through the sternum. Because of thesignificant risk and trauma of such procedures, left atrial appendageremoval occurs almost exclusively when the patient's chest is opened forother procedures, such as coronary artery bypass or valve surgery.

For that reason, alternative procedures which do not require opening ofthe patient's chest, i.e., a large median sternotomy, have beenproposed. U.S. Pat. No. 5,306,234 to Johnson describes a thoracoscopicprocedure where access to the pericardial space over the heart isachieved using a pair of intercostal penetrations (i.e., penetrationsbetween the patients ribs) to establish both visual and surgical access.While such procedures may be performed while the heart remains beating,they still require deflation of the patient's lung and that the patientbe placed under full anesthesia. Furthermore, placement of a chest tubeis typically required to re-inflate the lung, often requiring ahospitalization for a couple of days.

U.S. Pat. No. 5,865,791, to Whayne et al. describes a transvascularapproach for closing the left atrial appendage. Access is gained via thevenous system, typically through a femoral vein, a right internaljugular vein, or a subclavian vein, where a catheter is advanced in anantegrade direction to the right atrium. The intra-atrial septum is thenpenetrated, and the catheter passed into the left atrium. The catheteris then positioned in the vicinity of the left atrial appendage which isthen fused closed, e.g., using radiofrequency energy, other electricalenergy, thermal energy, surgical adhesives, or the like. Whayne et al.further describes a thoracoscopic procedure where the pericardium ispenetrated through the rib cage and a lasso placed to tie off the neckof the left atrial appendage. Other fixation means described includesutures, staples, shape memory wires, biocompatible adhesives, tissueablation, and the like. The transvascular approach suggested by Whayneet al. is advantageous in that it avoids the need to penetrate thepatient's chest but suffers from the need to penetrate the intra-atrialseptum, may not provide definitive closure, requires entry into the leftatrial appendage which may dislodge clot and requires injury to theendocardial surface which may promote thrombus formation. Athoracoscopic approach which is also suggested by Whayne et al. suffersfrom the same problems as the thoracoscopic approach suggested byJohnson.

Some improved and alternative methods and procedures for performingminimally invasive closure of the left atrial appendage are discussedin, e.g., U.S. Provisional Patent Application No. 60/826,413 filed on 21Sep. 2006, as well as in International Publication WO 2008/036408 A2,titled DEVICES AND METHODS FOR LIGATING ANATOMICAL STRUCTURES.

These methods and procedures may preferably be capable of beingperformed on patients who have received only local or generalanesthetic, whose hearts have not been stopped, and whose lungs are notdeflated. It would be further desirable to provide methods andprocedures which approach the left atrial appendage without the need toperform a thoracotomy (opening of the thorax) or the need to perform atranseptal penetration and/or perform the procedure within the leftatrium or left atrial appendage. More specifically, it would bepreferable to provide methods and procedures which permitted access tothe pericardial space from the xiphoid region of a patient's chest.

Closure of the left atrial appendage using a percutaneous approachtypically requires devices and techniques that can create a viableworking space in the pericardium and provide for direct visualization ofthe left atrial appendage within that space. The pericardial sac is,however, very slippery, often contains fluid and is under constantmotion. These factors make creating a viable working space for directvisualization difficult. Existing technologies are cumbersome (larger,non-steerable, two operator) and potentially traumatic to the cardiacarteries and veins on the epicardial surface. Unintentional trauma to acardiac artery could cause ischemia or perforations with potentiallyfatal outcomes for the patient.

Direct visualization, however, requires overcoming a number of technicalhurdles including creating a working space in the pericardial space tocreate a field of view for a videoscope or fiberscope a, removing fluids(blood) that can contaminate/obscure the lens, miniaturizing the toolsto be as atraumatic as possible, identifying various anatomy within thepericardial space using only direct sight and overcoming navigationissues with pointing the field of view at the desired target while theheart is beating. Unfortunately the intravascular tools also havesignificant drawbacks including the risks and complications of requiringa second percutaneous intravascular access point, a transseptalpuncture, causing endocardial trauma (potentially pro-thrombotic), andintroducing contrast agents into the circulatory system of patients.

SUMMARY

Navigation and tissue capture systems and methods for navigation toand/or capture of selected tissue using the innate electrical activityof the selected tissue and/or other tissue are described herein. In thecontext of left atrial appendage closure, the systems and methods can beused to navigate to the left atrial appendage and capture/control theappendage while a closure instrument (suture, clip, ring) is placed overthe appendage and tightened down or a closure method (ablation,cryogenic procedures, stapling, etc.) is performed to close the leftatrial appendage. As discussed herein, the use of innate electricalactivity for navigating devices may be used in connection with othertissues and/or areas of the body.

The systems and methods described herein may preferably be used inconnection with minimally invasive surgical techniques (e.g.,percutaneous, laparascopic, endoscopic, etc.) in which it can bedifficult to visualize the working field and/or where the availableworking space is limited. One example of such a situation isdemonstrated by techniques that require navigation within thepericardial space to, e.g., close the left atrial appendage. Thenavigation and capture systems and methods rely on the detection and/oridentification of innate electrical activity in the left atrialappendage or other tissue.

Although described in the context of left atrial appendage capture, thenavigation and tissue capture systems and methods described herein maybe used in any internal body location where detection and/oridentification of innate electrical activity can be used to navigate toand/or confirm that selected tissue is captured. Other electricallyactive tissues in the body with which the navigation/tissue capturesystems and methods could potentially be used may include, e.g., thegastrointestinal tract, central and/or peripheral nervous systems,skeletal muscle groups, etc. In any application, the systems and methodspreferably take advantage of differences in and/or existence of innateelectrical activity in tissues to identify tissue and/or facilitatenavigation. As a result, although the embodiments discussed herein arefocused on cardiac tissues, use in connection with other innatelyelectrically active tissues is possible.

With respect to systems and devices for navigating to and capturing theleft atrial appendage, the navigation and capture are preferablyaccomplished by monitoring cardiac electrical activity using one or moreelectrodes attached to one or more components of the systems as thedevices are advanced through the pericardial sac. In particular, thelocation of system components can preferably be determined bydistinguishing between the different intracardiac electrical signals(commonly referred to as an electrogram or “EGM”) associated withdifferent cardiac tissue. For example, an electrogram recorded overventricular epicardial myocardium tissue produces a distinct EGM signalas compared with the recording over atrial epicardial myocardium tissue.As a result, a user can determine whether the electrodes on the devicesare located proximate ventricular or atrial tissue based on the EGMobtained using the systems and methods described herein.

The systems and methods may preferably facilitate minimally invasivesurgical navigation to the left atrial appendage (or other anatomy withsufficiently electrically active tissue) through a small incision orneedle-stick access. The devices described herein may preferably bedelivered through an introducer and sheath (that is possibly steerableor deflectable). After access to the pericardial space has beenobtained, a guidewire may be placed in the pericardial space to helpguide the devices further into the pericardial space. The guidewireitself may optionally include electrodes that could be used to assistwith navigation of the guidewire to a desired location.

Each device described in connection with the systems and methods couldpotentially be delivered through such a sheath and into the pericardialsac. Although this technology could be used with a wide variety ofsurgical techniques, it may be well-suited for minimally invasivecatheter based procedures. Rather than passing through the rib cage, aswith some thoracoscopic techniques, the systems and methods describedherein may, for example, rely on a “sub-xiphoid” approach where thepercutaneous penetration is first made beneath the rib cage (preferablybetween the xiphoid and adjacent costal cartilage) and the device isadvanced through the penetration, over the epicardial surface (in thepericardial space) to reach a location adjacent to the exterior of theleft atrial appendage. Although a sub-xyphoid approach may be used, anyintrapericardial access may alternatively be used regardless of methodentry.

When this technique is used in this particular application, for example,the cardiac tissue encountered first is ventricular tissue which willyield an EGM indicative of ventricular cardiac tissue. As the systemcomponents are advanced towards atrial tissue (including, e.g., the leftatrial appendage), the EGM signal obtained using the system shouldchange and a unique EGM signal associated with atrial cardiac tissueshould be obtained. If the system components are advanced past the leftatrial appendage, the EGM signal obtained will typically have anon-atrial signature. Rather, advancement of the system components pastthe left atrial appendage may result in an EGM signal indicative of,e.g., the pericardium or far-field ventricular and atrial signals.

The navigation to and capture of the left atrial appendage may be usedto provide stability for subsequent procedures. The left atrialappendage may be stabilized and/or captured for any number of proceduresincluding ablation, drug delivery, isolation, ligation, diagnosticmapping, etc. The systems and methods described herein may help navigateto and locate the left atrial appendage through minimally invasiveapproaches.

Although the systems and methods described herein may use EGM signalsfor navigation and tissue capture with respect to the left atrialappendage, other navigation techniques may be used in combination withEGM-based navigation, such as, e.g., fluoroscopy, echogcardiography,MRI, CT scanning, ultrasonic imaging, direct visualization (using, e.g.,fiberoptic devices), etc.

For example, the methods described herein may include navigating adevice to an anatomical structure by delivering a device into theanatomical area; injecting image enhancement liquid into the anatomicalarea; and identifying the location of the device and/or the locations ofanatomical structures (e.g., the left atrial appendage) usingfluoroscopic or other imaging techniques that may be enhanced byinjection of the image enhancement liquid.

In one aspect, a navigation and tissue capture system may be providedthat includes a capture device having a first jaw and a second jaw,wherein the first jaw and the second jaw have an open configuration inwhich the first jaw and the second jaw are open and a closedconfiguration in which the first jaw and the second jaw are closed,wherein an interior surface of the first jaw is located closer to aninterior surface of the second jaw when the first jaw and the second jaware in the closed configuration than when the first jaw and the secondjaw are in the open configuration; a capture shaft having an elongatedbody with a proximal end and a distal end, wherein the distal end of thecapture shaft is attached to the capture device; a capture shaftelectrode attached to the capture shaft proximate the distal end of thecapture shaft, wherein the capture shaft electrode is located proximalof the capture device; a capture shaft electrode conductor extendingfrom the capture shaft electrode towards the proximal end of the captureshaft, wherein the capture shaft conductor includes an electricalmonitoring apparatus connector; a first electrode attached to thecapture device; and a first electrode lead extending from the firstelectrode towards the proximal end of the capture shaft, wherein thefirst electrode lead has an electrical monitoring apparatus connector.

In various embodiments, the systems described above may include one ormore of the following features: the first electrode may be exposed on aninterior surface of the first jaw of the capture device; the firstelectrode may occupy about one quarter or more of the interior surfaceof the first jaw; the first electrode may be exposed on an interiorsurface of the first jaw and the interior surface of the second jaw isfree of electrodes; the system may include a second electrode attachedto the capture device and a second electrode lead extending from thesecond electrode towards the proximal end of the capture shaft, whereinthe second electrode lead has an electrical monitoring apparatusconnector; the system may include an external electrode located on anexternal surface of the capture device; and an external electrode leadextending from the external electrode towards the proximal end of thecapture shaft, wherein the external electrode lead includes anelectrical monitoring apparatus connector; at least one of the first jawand the second jaw may rotate about an axis oriented generallytransverse to a longitudinal axis of the capture shaft when the firstjaw and the second jaw move between the open configuration and theclosed configuration, wherein the longitudinal axis extends between theproximal end and the distal end of the capture shaft; the capture devicemay be an atraumatic capture device; the capture shaft may include anactuator extending through the capture shaft to the capture device,wherein the actuator is operably attached to the capture device suchthat movement of the actuator within the capture shaft proximally anddistally moves the capture device between the closed configuration andthe open configuration; a locking mechanism capable of locking thecapture device in the closed configuration or the open configuration;etc.

In some embodiments, the navigation and tissue capture systems describedabove may include a delivery device having a proximal end, a distal end,and a capture lumen that includes an opening proximate the distal end ofthe delivery device, wherein a longitudinal axis extends between theproximal end and the distal end; wherein the capture device and thecapture shaft are sized for movement within the capture lumen of thedelivery device; and wherein the capture device has a deliveryconfiguration in which a distal end of the capture device is containedwithin the capture lumen, and wherein the capture device has an extendedconfiguration in which the distal end of the capture device extends outof the capture lumen proximate the distal end of the delivery device.The systems may also include a delivery device electrode attached to anexterior of the delivery device proximate the distal end of the capturedevice; and a delivery device electrode lead extending from the deliverydevice electrode towards the proximal end of the delivery device,wherein the delivery device electrode lead has an electrical monitoringapparatus connector; etc.

In some embodiments of systems described above that include a first andsecond electrode, one or more of the following features may be provided:the first electrode may be exposed on an interior surface of the firstjaw of the capture device and the second electrode may be exposed on aninterior surface of the second jaw of the capture device; the firstelectrode may be the only electrode on an interior surface of the firstjaw and the second electrode may be the only electrode on an interiorsurface of the second jaw; the first electrode may occupy about onequarter or more of the interior surface of the first jaw, and the secondelectrode may occupy about one quarter or more of the interior surfaceof the second jaw; the first electrode may be positioned on the firstjaw and the second electrode may be positioned on the second jaw suchthat closure of the first jaw and the second jaw in the absence oftissue between the first jaw and the second jaw places the firstelectrode and the second electrode in contact with each other; etc.

In some embodiments of systems described above that include a firstelectrode and a second electrode, the first electrode and the secondelectrode may be exposed on an interior surface of the first jaw of thecapture device; the interior surface of the second jaw may include anelectrically conductive surface such that closure of the first jaw andthe second jaw in the absence of tissue between the first jaw and thesecond jaw places the first electrode and the second electrode inelectrical communication with each other through the electricallyconductive surface; etc.

In another aspect, a method of navigating to selected internal bodytissue is described that includes delivering the capture device of anavigation and tissue capture system described herein to an internalbody location; monitoring innate electrical activity in tissue proximatethe internal body location using the capture shaft electrode; capturingtissue using the capture device; and monitoring innate electricalactivity in tissue captured by the capture device. In some embodiments,the internal body location may be the pericardial space and the capturedtissue may include the left atrial appendage.

In another aspect, a navigation and tissue capture system is describedthat includes a delivery device having a proximal end, a distal end, anda capture lumen having an opening proximate the distal end of thedelivery device, wherein a longitudinal axis extends between theproximal end and the distal end; a capture device sized for movementwithin the capture lumen of the delivery device, wherein the capturedevice has a delivery configuration in which a distal end of the capturedevice is contained within the capture lumen, and wherein the capturedevice has an extended configuration in which the distal end of thecapture device extends out of the capture lumen proximate the distal endof the delivery device; a capture shaft having a distal end operablyattached to the capture device, the capture shaft extending through thecapture lumen from a proximal end of the capture lumen to the capturedevice; a capture shaft electrode attached to the capture shaftproximate the distal end of the capture shaft, wherein the capture shaftelectrode is located proximal of the capture device; a capture shaftelectrode conductor extending from the capture shaft electrode towardsthe proximal end of the capture shaft, wherein the capture shaftconductor includes a connector adapted for connection to an EGMmonitoring apparatus; a primary capture electrode attached to thecapture device; and a primary capture electrode lead extending from theprimary capture electrode towards the proximal end of the deliverydevice, wherein the primary capture electrode lead includes a connectoradapted for connection to an EGM monitoring apparatus.

In another aspect, a navigation and tissue capture system may beprovided that includes a delivery device having a proximal end, a distalend, and a capture lumen having an opening proximate the distal end ofthe delivery device, wherein a longitudinal axis extends between theproximal end and the distal end; a capture device having a first jaw anda second jaw, wherein the first jaw and the second jaw have an openconfiguration in which the first jaw and the second jaw are open and aclosed configuration in which the first jaw and the second jaw areclosed; the capture device sized for movement within the capture lumenof the delivery device, wherein the capture device has a deliveryconfiguration in which a distal end of the capture device is containedwithin the capture lumen, and wherein the capture device has an extendedconfiguration in which the distal end of the capture device extends outof the capture lumen proximate the distal end of the delivery device; acapture shaft having a distal end operably attached to the capturedevice, the capture shaft extending through the capture lumen from aproximal end of the capture lumen to the capture device; a capture shaftelectrode attached to the capture shaft proximate the distal end of thecapture shaft, wherein the capture shaft electrode is located proximalof the capture device; a capture shaft electrode conductor extendingfrom the capture shaft electrode towards the proximal end of the captureshaft, wherein the capture shaft conductor includes an EGM monitoringapparatus connector; a first electrode exposed on an interior surface ofthe first jaw of the capture device; and a first electrode leadextending from the first electrode towards the proximal end of thedelivery device, wherein the first electrode lead includes an EGMmonitoring apparatus connector.

In various embodiments, the system described above may include one ormore of the following features: a second electrode exposed on aninterior surface of the second jaw of the capture device and a secondelectrode lead extending from the second electrode towards the proximalend of the delivery device, wherein the second electrode lead includesan EGM monitoring apparatus connector; the first electrode and thesecond electrode may be arranged such that closure of the first jaw andthe second jaw in the absence of tissue between the first jaw and thesecond jaw causes the first electrode and the second electrode tocontact each other; an external electrode may be located on an externalsurface of the first jaw; and an external electrode lead may extend fromthe external electrode towards the proximal end of the delivery device,wherein the external electrode lead includes an EGM monitoring apparatusconnector; the first electrode may occupy about one quarter or more ofthe interior surface of the first jaw; the capture shaft may include anactuator extending through the capture shaft to the capture device,wherein movement of the actuator within the capture shaft proximally anddistally moves the first jaw and the second jaw of the capture devicebetween the closed configuration and the open configuration; etc.

In another aspect, a navigation and tissue capture system may beprovided that includes a delivery device having a proximal end, a distalend, and a capture lumen with an opening proximate the distal end of thedelivery device, wherein a longitudinal axis extends between theproximal end and the distal end; a capture device having a first jaw anda second jaw, wherein the first jaw and the second jaw have an openconfiguration in which the first jaw and the second jaw are open and aclosed configuration in which the first jaw and the second jaw areclosed; the capture device sized for movement within the capture lumenof the delivery device, wherein the capture device has a deliveryconfiguration in which a distal end of the capture device is containedwithin the capture lumen, and wherein the capture device has an extendedconfiguration in which the distal end of the capture device extends outof the capture lumen proximate the distal end of the delivery device; acapture shaft having a distal end operably attached to the capturedevice, the capture shaft extending through the capture lumen from aproximal end of the capture lumen to the capture device; a capture shaftelectrode attached to the capture shaft proximate the distal end of thecapture shaft, wherein the capture shaft electrode is located proximalof the capture device; a capture shaft electrode conductor extendingfrom the capture shaft electrode towards the proximal end of the captureshaft, wherein the capture shaft conductor includes an EGM monitoringapparatus connector; a first electrode and a second electrode, whereinthe first electrode and the second electrode are exposed on an interiorsurface of the first jaw of the capture device; a first electrode leadextending from the first electrode towards the proximal end of thedelivery device, wherein the first electrode lead includes an EGMmonitoring apparatus connector; and a second electrode lead extendingfrom the second electrode towards the proximal end of the deliverydevice, wherein the second electrode lead includes an EGM monitoringapparatus connector.

In various embodiments, the system described above may include one ormore of the following features: the interior surface of the second jawmay include an electrically conductive surface such that closure of thefirst jaw and the second jaw in the absence of tissue between the firstjaw and the second jaw places the first electrode and the secondelectrode in electrical communication with each other through theelectrically conductive surface; an external electrode may be located onan external surface of the first jaw; and an external electrode lead mayextend from the external electrode towards the proximal end of thedelivery device, wherein the external electrode lead includes an EGMmonitoring apparatus connector; the capture shaft may include anactuator extending through the capture shaft to the capture device,wherein movement of the actuator within the capture shaft proximally anddistally moves the first jaw and the second jaw of the capture devicebetween the closed configuration and the open configuration; etc.

In another aspect, a navigation and tissue capture system may beprovided that includes a capture shaft having a proximal end and adistal end, wherein the capture shaft defines a longitudinal axisextending from the proximal end to the distal end; a capture deviceattached to the distal end of the capture shaft, the capture devicehaving a first jaw and a second jaw, wherein the capture device has aclosed configuration in which the first jaw and the second jaw areclosed and an open configuration in which the first jaw and the secondjaw are open; and wherein at least one of the first jaw and the secondjaw rotate about an axis oriented generally transverse to thelongitudinal axis of the capture shaft when the first jaw and the secondjaw move between the open configuration and the closed configuration; acapture shaft electrode attached to the capture shaft proximate thedistal end of the capture shaft, wherein the capture shaft electrode islocated proximal of the capture device; a capture shaft electrodeconductor extending from the capture shaft electrode towards theproximal end of the capture shaft, wherein the capture shaft conductorincludes an EGM monitoring apparatus connector; a first electrodeexposed on an interior surface of the first jaw of the capture device;and a first electrode lead extending from the first electrode towardsthe proximal end of the delivery device, wherein the first electrodelead includes an EGM monitoring apparatus connector.

In various embodiments, the system described above may include one ormore of the following features: a second electrode exposed on aninterior surface of the second jaw of the capture device and a secondelectrode lead extending from the second electrode towards the proximalend of the delivery device, wherein the second electrode lead includesan EGM monitoring apparatus connector; the first electrode may bepositioned on the first jaw and the second electrode may be positionedon the second jaw such that closure of the first jaw and the second jawin the absence of tissue between the first jaw and the second jaw placesthe first electrode and the second electrode in contact with each other;an external electrode may be located on an external surface of at leastone of the first jaw and the second jaw, and an external electrode leadmay extend from the external electrode towards the proximal end of thedelivery device, wherein the external electrode lead includes an EGMmonitoring apparatus connector; the first electrode may occupy about onequarter or more of the interior surface of the first jaw; the captureshaft may include an actuator extending through the capture shaft to thecapture device, wherein movement of the actuator within the captureshaft proximally and distally moves the capture device between theclosed configuration and the open configuration; etc.

In another aspect, a navigation and tissue capture system may beprovided that includes a capture shaft having a proximal end and adistal end, wherein the capture shaft defines a longitudinal axisextending from the proximal end to the distal end; a capture deviceattached to the distal end of the capture shaft, the capture devicehaving a first jaw and a second jaw, wherein the capture device has aclosed configuration in which the first jaw and the second jaw areclosed and an open configuration in which the first jaw and the secondjaw are open; and wherein at least one of the first jaw and the secondjaw rotate about an axis oriented generally transverse to thelongitudinal axis of the capture shaft when the first jaw and the secondjaw move between the open configuration and the closed configuration; anexternal electrode located on an external surface of at least one of thefirst jaw and the second jaw; and an external electrode lead extendingfrom the external electrode towards the proximal end of the deliverydevice, wherein the external electrode lead includes an EGM monitoringapparatus connector; a first electrode exposed on an interior surface ofthe first jaw of the capture device; and a first electrode leadextending from the first electrode towards the proximal end of thedelivery device, wherein the first electrode lead includes an EGMmonitoring apparatus connector.

In various embodiments, the systems described above may include one ormore of the following features: a second electrode exposed on aninterior surface of the second jaw of the capture device and a secondelectrode lead extending from the second electrode towards the proximalend of the delivery device, wherein the second electrode lead includesan EGM monitoring apparatus connector; the first electrode positioned onthe first jaw and the second electrode positioned on the second jaw suchthat closure of the first jaw and the second jaw in the absence oftissue between the first jaw and the second jaw places the firstelectrode and the second electrode in contact with each other; the firstelectrode may occupy about one quarter or more of the interior surfaceof the first jaw; the capture shaft having an actuator extending throughthe capture shaft to the capture device, wherein movement of theactuator within the capture shaft proximally and distally moves thecapture device between the closed configuration and the openconfiguration; etc.

In another aspect, a navigation and tissue capture system may beprovided that includes a capture shaft having a proximal end and adistal end, wherein the capture shaft defines a longitudinal axisextending from the proximal end to the distal end; a capture deviceattached to the distal end of the capture shaft, the capture devicehaving a first jaw and a second jaw, wherein the capture device has aclosed configuration in which the first jaw and the second jaw areclosed and an open configuration in which the first jaw and the secondjaw are open, wherein an interior surface of the first jaw is locatedcloser to an interior surface of the second jaw when the first jaw andthe second jaw are in the closed configuration than when the first jawand the second jaw are in the open configuration; an electrode exposedon an interior surface of the first jaw of the capture device; and afirst electrode lead extending from the first electrode towards theproximal end of the delivery device, wherein the first electrode leadincludes an EGM monitoring apparatus connector; wherein the interiorsurface of the second jaw does not contain any electrodes capable ofsensing innate electrical activity of tissue located between the firstjaw and the second jaw.

In another aspect, a navigation and tissue capture system may beprovided that includes a capture shaft having a proximal end and adistal end, wherein the capture shaft defines a longitudinal axisextending from the proximal end to the distal end; a capture deviceattached to the distal end of the capture shaft, the capture devicehaving a first jaw and a second jaw, wherein the capture device has aclosed configuration in which the first jaw and the second jaw areclosed and an open configuration in which the first jaw and the secondjaw are open, wherein an interior surface of the first jaw is locatedcloser to an interior surface of the second jaw when the first jaw andthe second jaw are in the closed configuration than when the first jawand the second jaw are in the open configuration; a first electrodeexposed on an interior surface of the first jaw of the capture device,wherein the first electrode occupies about one quarter or more of theinterior surface of the first jaw; and a first electrode lead extendingfrom the first electrode towards the proximal end of the deliverydevice, wherein the first electrode lead includes an EGM monitoringapparatus connector.

In another aspect, a navigation and tissue capture system may beprovided that includes a delivery device having a proximal end, a distalend, and a capture lumen having an opening proximate the distal end ofthe delivery device, wherein a longitudinal axis extends between theproximal end and the distal end; a delivery device electrode attached tothe delivery device proximate the distal end of the delivery device; adelivery device electrode lead extending from the delivery deviceelectrode towards the proximal end of the delivery device, wherein thedelivery device electrode lead includes a connector adapted forconnection to an EGM monitoring apparatus; a capture device sized formovement within the capture lumen of the delivery device, wherein thecapture device has a delivery configuration in which a distal end of thecapture device is contained within the capture lumen, and wherein thecapture device has an extended configuration in which the distal end ofthe capture device extends out of the capture lumen proximate the distalend of the delivery device; a primary capture electrode attached to thecapture device; and a primary capture electrode lead extending from theprimary capture electrode towards the proximal end of the deliverydevice, wherein the primary capture electrode lead includes a connectoradapted for connection to an EGM monitoring apparatus.

In various embodiments, the system described above may include one ormore of the following features: the primary capture electrode is locatedwithin the capture lumen when the capture device is in the deliveryconfiguration, and wherein the primary capture electrode is locatedoutside of the capture lumen when the capture device is in the extendedconfiguration; the capture device includes a grasping apparatus having afirst jaw and a second jaw, wherein closure of the grasping apparatusincludes movement of the first jaw and the second jaw towards each otherto capture tissue between the first jaw and the second jaw; the primarycapture electrode is attached to the first jaw; the capture deviceincludes an auxiliary capture electrode attached to the second jaw; theprimary capture electrode and the auxiliary capture electrode arearranged such that closure of the grasping apparatus in the absence oftissue between the first jaw and the second jaw causes the primaryelectrode and the auxiliary electrode to contact each other; the firstjaw and the second jaw are arranged opposite from each other, andwherein the first jaw and the second jaw both have an internal surfacefacing the opposing jaw and an external surface facing away from theopposing jaw, and further wherein the primary capture electrode islocated on one of the external surfaces of the first jaw and the secondjaw; a first jaw electrode located on the internal surface of the firstjaw and a second jaw electrode located on the internal surface of thesecond jaw, and further wherein the first jaw electrode and the secondjaw electrode are arranged such that closure of the grasping apparatusin the absence of tissue between the first jaw and the second jaw causesthe first jaw electrode and the second jaw electrode to contact eachother; the capture device includes a cage; the delivery device includesa ligation lumen having a ligation opening proximate the distal end ofthe delivery device; etc.

In another aspect, a navigation and tissue capture system may beprovided that includes a delivery device comprising a proximal end, adistal end, and a capture lumen comprising an opening proximate thedistal end of the delivery device, wherein a longitudinal axis extendsbetween the proximal end and the distal end; a capture device sized formovement within the capture lumen of the delivery device, wherein thecapture device includes a delivery configuration in which a distal endof the capture device is contained within the capture lumen, and whereinthe capture device has an extended configuration in which the distal endof the capture device extends out of the capture lumen proximate thedistal end of the delivery device; a primary capture electrode attachedto the capture device; and a primary capture electrode lead extendingfrom the primary capture electrode towards the proximal end of thedelivery device, wherein the primary capture electrode lead includes aconnector adapted for connection to an EGM monitoring apparatus.

In various embodiments, the system described above may include one ormore of the following features: the primary capture electrode is locatedwithin the capture lumen when the capture device is in the deliveryconfiguration, and wherein the primary capture electrode is locatedoutside of the capture lumen when the capture device is in the extendedconfiguration; the capture device includes a grasping apparatus having afirst jaw and a second jaw, wherein closure of the grasping apparatusincludes movement of the first jaw and the second jaw towards each otherto capture tissue between the first jaw and the second jaw; the primarycapture electrode is attached to the first jaw; the capture deviceincludes an auxiliary capture electrode attached to the second jaw; theprimary capture electrode and the auxiliary capture electrode arearranged such that closure of the grasping apparatus in the absence oftissue between the first jaw and the second jaw causes the primaryelectrode and the auxiliary electrode to contact each other; the firstjaw and the second jaw are arranged opposite from each other, andwherein the first jaw and the second jaw both have an internal surfacefacing the opposing jaw and an external surface facing away from theopposing jaw, and further wherein the primary capture electrode islocated on one of the external surfaces of the first jaw and the secondjaw; a first jaw electrode located on the internal surface of the firstjaw and a second jaw electrode located on the internal surface of thesecond jaw, and further wherein the first jaw electrode and the secondjaw electrode are arranged such that closure of the grasping apparatusin the absence of tissue between the first jaw and the second jaw causesthe first jaw electrode and the second jaw electrode to contact eachother; the capture device includes a cage; the delivery device includesa ligation lumen having a ligation opening proximate the distal end ofthe delivery device; etc.

Any of the navigation and tissue capture systems described herein mayinclude an EGM monitor device capable of displaying EGM signals obtainedfrom one or more electrodes provided in the systems.

Any of the navigation and tissue capture systems described herein mayinclude a delivery device and/or a capture shaft that includes at leastone image enhancement liquid injection lumen having an injection openingproximate the distal end of the delivery device and/or the captureshaft.

In another aspect, a kit may be provided that includes any of thenavigation and tissue capture systems described herein along with animage enhancement liquid injection device. The kit may further include acontainer of image enhancement liquid.

In another aspect, a method of navigating a device to the left atrialappendage may be provided that includes delivering a device into thepericardial sac; detecting an EGM signal within the pericardial sacusing one or more electrodes on the device; identifying the location ofthe device relative to the left atrial appendage by determining if theEGM signal is associated with atrial epicardial tissue; optionallyconfirming capture of the left atrial appendage by a capture device bydetermining if an EGM signal obtained from tissue captured by thecapture device is associated with tissue of the left atrial appendage;and optionally confirming capture of atrial tissue by electricallystimulating the atrial tissue and confirming that the tissue is beingpaced.

In various embodiments, the methods described above may includeinjecting image enhancement liquid within the pericardial sac using oneor more image enhancement liquid injector lumens on the device; andidentifying the location of the device relative to the left atrialappendage using an imaging technique.

In another aspect, a navigation and tissue capture system is providedthat includes a delivery device having a proximal end, a distal end, anda capture lumen that includes an opening proximate the distal end of thedelivery device, wherein a longitudinal axis extends between theproximal end and the distal end; a delivery device electrode attached tothe delivery device proximate the distal end of the delivery device; adelivery device electrode lead extending from the delivery deviceelectrode towards the proximal end of the delivery device, wherein thedelivery device electrode lead comprises a connector adapted forconnection to an EGM monitoring apparatus; a capture device sized formovement within the capture lumen of the delivery device, wherein thecapture device has a delivery configuration in which a distal end of thecapture device is contained within the capture lumen, and wherein thecapture device has an extended configuration in which the distal end ofthe capture device extends out of the capture lumen proximate the distalend of the delivery device; a primary capture electrode attached to thecapture device; and a primary capture electrode lead extending from theprimary capture electrode towards the proximal end of the deliverydevice, wherein the primary capture electrode lead includes a connectoradapted for connection to an EGM monitoring apparatus.

In various aspects, the systems may include one or more of the followingfeatures. The primary capture electrode may be located within thecapture lumen when the capture device is in the delivery configuration,and the primary capture electrode may be located outside of the capturelumen when the capture device is in the extended configuration. Thecapture device may be a grasping apparatus that includes a first jaw anda second jaw, wherein closure of the grasping apparatus includesmovement of the first jaw and the second jaw towards each other tocapture tissue between the first jaw and the second jaw; the primarycapture electrode may be attached to the first jaw; the capture devicemay include an auxiliary capture electrode attached to the second jaw.The primary capture electrode and the auxiliary capture electrode may bearranged such that closure of the grasping apparatus in the absence oftissue between the first jaw and the second jaw causes the primaryelectrode and the auxiliary electrode to contact each other. The firstjaw and the second jaw may be arranged opposite from each other, andwherein the first jaw and the second jaw both include an internalsurface facing the opposing jaw and an external surface facing away fromthe opposing jaw, and further wherein the primary capture electrode islocated on one of the external surfaces of the first jaw and the secondjaw. A first jaw electrode may be located on the internal surface of thefirst jaw and a second jaw electrode may be located on the internalsurface of the second jaw, wherein the first jaw electrode and thesecond jaw electrode may be arranged such that closure of the graspingapparatus in the absence of tissue between the first jaw and the secondjaw causes the first jaw electrode and the second jaw electrode tocontact each other. The system may include a return and/or trackingelectrode adapted for attachment to the skin of a patient. The capturedevice may include a barbed hook, a tissue screw; a cryogenic device; acage, a lasso, a suction device, adhesive, RF energy, etc. The deliverydevice may include a ligation lumen having a ligation opening proximatethe distal end of the delivery device. The system may include an EGMmonitor device capable of displaying EGM signals obtained from one ormore electrodes of the tissue capture system.

In another aspect, a navigation and tissue capture system may beprovided that includes a delivery device having a proximal end, a distalend, and a capture lumen that includes an opening proximate the distalend of the delivery device, wherein a longitudinal axis extends betweenthe proximal end and the distal end; a capture device sized for movementwithin the capture lumen of the delivery device, wherein the capturedevice has a delivery configuration in which a distal end of the capturedevice is contained within the capture lumen, and wherein the capturedevice has an extended configuration in which the distal end of thecapture device extends out of the capture lumen proximate the distal endof the delivery device; a primary capture electrode attached to thecapture device; and a primary capture electrode lead extending from theprimary capture electrode towards the proximal end of the deliverydevice, wherein the primary capture electrode lead includes a connectoradapted for connection to an EGM monitoring apparatus.

In various aspects, the navigation and tissue capture system describedabove may include one or more of the following features. The primarycapture electrode may be located within the capture lumen when thecapture device is in the delivery configuration, and the primary captureelectrode may be located outside of the capture lumen when the capturedevice is in the extended configuration. The capture device may includea grasping apparatus having a first jaw and a second jaw, whereinclosure of the grasping apparatus includes movement of the first jaw andthe second jaw towards each other to capture tissue between the firstjaw and the second jaw. The primary capture electrode may be attached tothe first jaw. The capture device may include an auxiliary captureelectrode attached to the second jaw. The primary capture electrode andthe auxiliary capture electrode may be arranged such that closure of thegrasping apparatus in the absence of tissue between the first jaw andthe second jaw causes the primary electrode and the auxiliary electrodeto contact each other. The first jaw and the second jaw are arrangedopposite from each other, and the first jaw and the second jaw bothinclude an internal surface facing the opposing jaw and an externalsurface facing away from the opposing jaw, and further wherein theprimary capture electrode is located on one of the external surfaces ofthe first jaw and the second jaw. A first jaw electrode may be locatedon the internal surface of the first jaw and a second jaw electrode maybe located on the internal surface of the second jaw, and furtherwherein the first jaw electrode and the second jaw electrode may bearranged such that closure of the grasping apparatus in the absence oftissue between the first jaw and the second jaw causes the first jawelectrode and the second jaw electrode to contact each other. The systemmay include a return electrode adapted for attachment to the skin of apatient. The capture device may include a barbed hook, a tissue screw; acryogenic device; a cage, a lasso, a suction device, adhesive, etc. Thedelivery device may include a ligation lumen comprising a ligationopening proximate the distal end of the delivery device. The system mayinclude an EGM monitor device capable of displaying EGM signals obtainedfrom one or more electrodes of the tissue capture system. The system mayinclude a device operable for delivering image enhancement liquid to thedistal end of the device to determine the location of the device and/orthe locations of anatomical structures (e.g., the left atrial appendage)using fluoroscopic and/or other imaging techniques.

In another aspect, a method is provided that may include navigating adevice to the left atrial appendage by delivering a device into thepericardial sac; detecting an EGM signal within the pericardial sacusing one or more electrodes on the device; identifying the location ofthe device relative to the left atrial appendage by determining if theEGM signal is associated with atrial epicardial tissue; optionallyconfirming capture of the left atrial appendage by a capture device bydetermining if an EGM signal obtained from tissue captured by thecapture device is associated with tissue of the left atrial appendage.

The words “preferred” and “preferably” refer to embodiments that mayafford certain benefits, under certain circumstances. However, otherembodiments may also be preferred, under the same or othercircumstances. Furthermore, the recitation of one or more preferredembodiments does not imply that other embodiments are not useful, and isnot intended to exclude other embodiments from the scope of theinvention.

As used herein, “a,”, “the,” “at least one,” and “one or more” are usedinterchangeably. Thus, for example, an electrode may be used to refer toone, two, three or more electrodes.

The term “and/or” means one or all of the listed elements or acombination of any two or more of the listed elements.

The above summary is not intended to describe each embodiment or everyimplementation of the navigation and tissue capture systems describedherein. Rather, a more complete understanding of the navigation andtissue capture systems described herein will become apparent andappreciated by reference to the following Detailed Description ofExemplary Embodiments and claims in view of the accompanying figures ofthe drawing.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING

FIG. 1 depicts one exemplary embodiment of a delivery device with acapture device extending out of a delivery lumen in the delivery device.

FIG. 2A depicts another exemplary embodiment of a delivery deviceincluding a mapping device extending therefrom.

FIG. 2B depicts another exemplary embodiment of a delivery device with acapture device extending out of a delivery lumen in the delivery deviceand a mapping device extending out of the capture device.

FIG. 3 depicts another exemplary embodiment of a delivery device with acapture device extending out of a delivery lumen in the delivery device.

FIG. 4 is a cross-sectional view of a human heart showing the left sideanatomy, with the delivery device and capture device of FIG. 1 on theepicardial surface of the human heart.

FIG. 5 depicts an exemplary EGM signal from of a normal heartbeat (orcardiac cycle) including a P wave, a QRS complex and a T wave. The EGMsignal corresponds to the depolarization of the atria and ventricles.

FIGS. 6A-6C depict exemplary electrocardiogram (EGM) signals seen as adevice is advanced from the apex of the human heart towards the leftatrial appendage.

FIG. 7 is a cross-sectional view of the human heart showing the leftside anatomy, with the capture device of FIG. 1 capturing the leftatrial appendage.

FIG. 8A depicts a representative electrogram (EGM) across the interiorelectrodes on the jaws of the capture device of FIG. 7.

FIG. 8B depicts a representative electrogram (EGM) as detected by theexternal electrode while grasping the left atrial appendage tissue.

FIG. 9 is a cross-sectional view of the human heart depicting closure ofthe capture device of FIG. 1 in a situation where the capture devicedoes not capture left atrial appendage tissue.

FIG. 10A depicts a representative electrogram (EGM) across the interiorelectrodes on the jaws of the capture device of FIG. 9 when the jaws donot capture tissue.

FIG. 10B depicts a representative electrogram (EGM) as detected usingthe exterior electrode when the jaws do capture left atrial appendagetissue.

FIG. 11 is a cross-sectional view of the human heart depictingadvancement of a capture device past the distal tip of the left atrialappendage lobe.

FIG. 12 is a cross-sectional view of the human heart depicting thecapture device after advancement beneath the distal tip of the leftatrial appendage lobe.

FIG. 13A depicts a representative electrogram (EGM) across the interiorelectrodes on the jaws of the capture device of FIG. 12.

FIG. 13B depicts a representative electrogram (EGM) as detected by theexterior electrode on the capture device of FIG. 12.

FIG. 14 depicts another exemplary embodiment of a delivery device with acapture device extending out of a delivery lumen in the delivery device.

FIG. 15 depicts another exemplary embodiment of a delivery device with acapture device extending out of a delivery lumen in the delivery device.

FIG. 16 depicts another exemplary embodiment of a delivery device with acapture device and a guiding element extending out of a delivery lumenin the delivery device.

FIG. 17 depicts another exemplary embodiment of a capture device.

FIG. 18 is an enlarged perspective view of the distal end portion of oneembodiment of a capture device in an open configuration.

FIG. 19 is an enlarged perspective view of the capture device of FIG. 18in a closed configuration.

FIG. 20 is a side elevational view of the capture device of FIG. 18.

FIG. 21A depicts an exemplary device injecting image enhancement liquidinto the pericardial sac to outline the left atrial appendage.

FIG. 21B depicts an image enhancement liquid filling the voids betweenthe left atrial appendage and the epicardial surface of the heart.

FIG. 22A is a cross-sectional view of an exemplary sheath introducerincluding a image enhancement liquid injection lumen.

FIG. 22B is a cross-section view of another exemplary sheath introducerincluding multiple image enhancement liquid injection lumens.

FIG. 23A depicts an exemplary capture device including multiple imageenhancement liquid injection catheters.

FIG. 23B depicts another exemplary capture device including a imageenhancement liquid injection catheter.

FIG. 24 is a schematic diagram of a system including a capture deviceand a ligation device being delivered through a delivery device.

FIG. 25 is a schematic of one system including electrodes operablyconnected to an electrical activity (e.g., EGM) monitoring device.

FIGS. 26-35 depict electrodes on various devices that may be used inconnection with the navigation and tissue capture systems describedherein.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of exemplary embodiments,reference is made to the accompanying figures of the drawing which forma part hereof, and in which are shown, by way of illustration, specificembodiments in which the systems and/or methods may be practiced. It isto be understood that other embodiments may be utilized and structuralchanges may be made without departing from the scope of the presentinvention.

One exemplary embodiment of a tissue capture system including a deliverydevice 10 and a capture device 20 is depicted in FIG. 1. The deliverydevice 10 may be provided in the form of, e.g., a sheath (that may ormay not be provided with an introducer as is known), catheter, or otherelongate structure. The delivery device 10 may or may not be flexible.The delivery device 10 itself may preferably be steerable ordeflectable. The delivery device 10 is also optional, i.e., thenavigation and tissue capture systems described herein may not include adelivery sheath.

The proximal end of the capture device 20 may preferably include a userinterface that allows an operator to deploy and retract the capturedevice 20 from within the delivery device 10, a mechanism to actuate thecapture device 20, and optionally a mechanism to steer the capturedevice separately from the delivery device 10.

In the depicted embodiment, the delivery device 10 includes a lumenthrough which the capture device 20 can be advanced or retracted toassist with delivery of the capture device 20 to a selected internalbody location. Although the delivery device 10 may include as few as onelumen as depicted in FIG. 1, it may include two or more lumens that maybe used to provide pathways to deliver other devices, provide visualaccess, fluid access, etc. The capture device 20 may preferably extendout of the proximal end of the delivery device 10 such that it can becontrolled by a user also operating the delivery device 10 as isconventional in the use of minimally invasive surgical devices.

The capture device 20 is depicted in FIG. 1 in an extended configurationin which the distal end of the capture device 20 extends out of thelumen in the delivery device 10 proximate the distal end of the deliverydevice 10. Although not depicted, the capture device 20 is preferablymovable within the lumen of the delivery device 10 such that the capturedevice 20 can be moved between the extended position depicted in FIG. 1and a delivery configuration in which a distal end of the capture device20 is contained within the lumen of the delivery device 10. A potentialbenefit of having the capture device 20 retracted into the deliverydevice 10 during delivery is a reduction in the likelihood of trauma tothe epicardial surface at the delivery site and on the path to thedelivery site (e.g., a left atrial appendage).

The capture device 20 depicted in FIG. 1 is in the form of a graspingapparatus that includes two jaws 22 and 24. The jaws 22 and 24 canpreferably be moved between on open position adapted to allow tissue toenter the space between the open jaws 22 and 24 and a closed position inthe jaws 22 and 24 are moved towards each other to capture tissue thatcan be grasped between the jaws 22 and 24. The jaws of the graspingapparatus can be actuated by any suitable technique (e.g., mechanicallinkage, memory material that is closed when drawn into the deliverydevice, electrical activation, hydraulically, pneumatically,magnetically, etc.). Although the grasping apparatus of the capturedevice 20 includes two jaws, it should be understood that other graspingapparatus may be provided that include three or more jaws (and thatother apparatus for capturing tissue may be used in place of, or inaddition to, apparatus that use jaws).

Also, although the exemplary systems and methods are described inconnection with a grasping apparatus as a tissue capture device, itshould be understood that the systems and methods may be used inconnection with a wide variety of capture devices. Potentially usefulalternative capture devices may include, but are not limited to, helixgroups, cryogenic tips, barbed hooks, cages, adhesive structures,suction, laser energy, RF energy, etc. Examples of some potentiallysuitable capture devices and/or systems may be described in U.S. Pat.No. 7,338,434; U.S. Pat. No. 7,141,057; U.S. Pat. No. 7,276,235; U.S.Pat. No. 6,206,827; etc.

The capture device 20 depicted in FIG. 1 includes electrodes that can beused to detect EGM signals for navigating the delivery device 10 and thecapture device 20. The particular arrangement of electrodes depicted inconnection with the system of FIG. 1 includes electrodes 32, 34, and 36.The electrode 32 may be located on an external surface 21 of the jaw 22(where the external surface 21 is the surface of the jaw 22 that facesaway from the opposing jaw 24). The electrode 34 may be located on aninternal surface 23 of the jaw 22 (where the internal surface 23 is thesurface of the jaw 22 that faces the opposing jaw 24). The electrode 36may be located on an internal surface 25 of the jaw 24 (where theinternal surface 25 is the surface of the jaw 24 that faces the opposingjaw 22). The electrodes may be placed in any suitable location along thelength of the jaws, e.g., the distal end, proximal end or anyintermediate location.

The proximal end of the capture device 20 preferably includes connectorsconnected to each electrode on the distal end of the capture device 20by leads such that the electrodes can be connected to a system capableof generating user-readable plots of the electrical energy detectedusing the electrodes. Such systems will be well-known to those ofskilled in the art. For example, when inside the pericardial space, theelectrodes at the working or distal end of the capture device 20 can beused to detect the electrogram (EGM) on the epicardial surface of thepatient's heart. Any or all of the electrodes may be monopolar ormultipolar, as desired.

FIG. 2A depicts another system that may be used to navigate to andcapture selected tissue. In this depicted embodiment, the deliverydevice 110 a includes two lumens 112 a and 114 a, with the lumen 112 apreferably being used to delivery a capture device (not shown). Thelumen 114 a is used to deliver a mapping device 140 a that, in thedepicted embodiment, can be extended out of the lumen 114 a.

The mapping device 140 a may be in the form of, e.g., a conventionalelectrophysiology mapping catheter. The mapping device 140 a may includeas few as one electrode 142 a or two or more electrodes 142 a. Theelectrode or electrodes 142 a may be monopolar or multipolar.

Although the delivery device 110 a could be used with a capture devicedeployed down the lumen 112 a as described above, the delivery devicecould potentially include a capture device delivered through the samelumen as the mapping device 140 a (with the mapping device beingdeployed, e.g., through a channel provided in the capture deviceitself). Secondly the device in FIG. 2 may be used independently to findthe left atrial appendage based on the electrocardiogram (EGM) and thenheld in place while a second stabilization/capture device (mechanicalgrasper, helix group, cryo tip, barbed hook) was deployed to the samelocation (e.g., over the mapping device 140 a or over the deliverydevice 110 a) to grab/stabilize the required tissue.

An embodiment in which a mapping device 140 b is delivered through alumen provided in the capture device 120 itself is depicted in FIG. 2B.The mapping device 140 b may preferably include an electrode 142 b atits distal-most end and/or merely proximate its distal-most end. Thecapture device 120 b may include jaws 122 b and 124 b that may be usedto grasp tissue as described herein. The jaws 122 b and 124 b and/or thedelivery device 110 b may or may not include electrodes to assist withnavigation.

In the embodiment depicted in FIG. 2B, the capture device 120 b mayinclude, for example, a capture shaft (see, e.g., FIGS. 18-20) thatincludes a lumen through which the mapping device 140 b can be advancedand/or retracted. In use, the mapping device 140 b may be advanced aheadof the capture device 120 b to detect electrical signals in tissue thatwould then be contacted by the capture device 120 b if it were advancedover the mapping device 140 b.

Although the depicted embodiment includes a capture device 120 b withopen jaws, in some embodiments, the capture device may be retained in aclosed position while the mapping device is advanced through the closedcapture device. In still another variation, the capture device 120 b mayeven be retained within the delivery device 110 b while the mappingdevice 140 b is advanced out of the delivery device 110 b.

FIG. 3 depicts another exemplary embodiment of a navigation and tissuecapture system that includes a delivery device 210 and a capture device220. In most respects, the delivery device 210 and the capture device220 are similar to those depicted and described in connection withFIG. 1. Among the differences are that the delivery device 210 itselfincludes an electrode 216 located near or proximate its distal end.Although only one electrode 216 is depicted, the delivery device 210 mayinclude two or more electrodes. Also, any electrodes included with thedelivery device 210 may be monopolar or multipolar. The electrode 216may be in the form of a ring electrode as depicted. Alternatively, theelectrode or electrodes provided on the delivery device 210 may not bein the form of ring electrodes.

The capture device 220 depicted in FIG. 3 also includes electrodes 234and 236 on the internal surfaces of the jaws 222 and 224. Although notdepicted, the capture device 220 may include other electrodes on, e.g.,one or more of the external surfaces of the jaws 222 and 224. Theelectrode 216 on the delivery device 210 may potentially be used inconjunction with electrodes 234 and 236 on the jaws 222 and 224 toimprove navigation and/or to establish the position of the distal end ofthe capture device 220. The electrode 216 on the delivery device 210could be used by the operator to help differentiate between tissue(e.g., ventricular and atrial tissue) before the capture device 220 isextended out of the delivery device 210.

One potential advantage of the system depicted in FIG. 3 may be that thedistal end of the delivery device 210 could be less traumatic (e.g.,softer, smoother, etc.) to the surrounding tissue (e.g., the epicardialsurface of the heart) than the capture device 220. After the distal endof the delivery device 210 is in or near a selected internal bodylocation (e.g., the pericardial space) the delivery device 210 (whichmay preferably be steerable/deflectable) could be navigated to aselected location using the electrode 216 on the delivery device 210(while the capture device 220 and its electrodes remain in the deliverydevice 210).

After the distal end of the delivery device is in or near the selectedtissue to captured, the capture device 220 may be deployed from thedelivery device 210. The electrode or electrodes on the capture devicemay then be used (alone or in conjunction with the electrode 216 on thedelivery device 210) to navigate the capture device 220 to the selectedtissue. The electrodes on the capture device 220 may, for example, beable to more accurately assess tissue differentiation. The electrode 216on the delivery device may, for example, be monitored to determine ifthe delivery device 210 moves during deployment and use of the capturedevice 220 (for example, a change in EGM signal seen using the electrode216 during the grasping of the left atrial appendage may indicate thatthe delivery device 210 has moved to a less desirable location).

A cross-sectional view of the left side of the human heart is depictedin FIG. 4 and will be used to describe operation of one embodiment of anavigation and tissue capture system. The heart as depicted includes theleft atrium 50 and left ventricle 52. The left atrial appendage 54extends from the left atrium 50 and includes a distal tip or leadingedge 56.

Also depicted in FIG. 4 is the navigation and capture system of, e.g.,FIG. 1 including a delivery device 10 and a capture device 20. Thecapture device 20 includes an external electrode 32 on an externalsurface of one jaw of the capture device 20 and a pair of internalelectrodes 34 and 36 on the internal surfaces of the jaws. The deliverydevice 10 is depicted as approaching the left atrial appendage 54 fromthe apex of the heart (which would be typical for a sub-xiphoidapproach).

The distal end of the capture device 20 is advanced along the epicardialsurface (over, e.g., the left ventricle 52) towards the leading edge 56of the left atrial appendage 54. As can be seen in FIG. 4, a capturedevice 20 that progresses along the epicardial surface coming from theapex of the heart is primarily in contact with ventricular myocardiumtissue 52 until it reaches the leading edge 56 of the left atrialappendage 54. Although not depicted in FIG. 4, there is a thinpericardial membrane that covers the entire epicardial surface of theheart. This pericardial membrane is electrically inactive and does notproduce an independent EGM signal.

Ventricular epicardial myocardium tissue 52 produces a distinct EGMcompared with the EGM produced by atrial epicardial myocardium tissuesuch as that found in the leading edge 56 of the left atrial appendage54. As the capture device 20 advances across the ventricular epicardialmyocardium tissue 52 on the epicardial surface of the heart, theelectrodes 32 and 36 will primarily capture only ventricular EGMsignals. Although not depicted, the delivery device 10 may, itself, alsoinclude one or more electrodes (as, for example, described in the systemof FIG. 3). Such electrodes may be used in addition to or in place ofthe electrodes on the capture device 20 (which may or may not beextended out of the delivery device 10).

Depending on the orientation, number, and/or positions of the variouselectrodes, it may be possible to detect non-ventricular signals on someof the electrodes. For example, electrode 36 may not be in contact withany ventricular tissue and, thus, may detect a minimal EGM signal, whilethe electrode 32 may be in direct contact with the ventricularmyocardium 52 and would likely show a strong near-field ventricular EGMsignal.

The device can optionally be designed to maintain orientation such thatany one electrode could be maintained in one stationary locationrelative to a selected part of the anatomy. With respect to FIG. 4, forexample, it may be desirable to keep electrode 32 on the epicardialsurface versus on the pericardium. That positioning could potentially bemaintained by monitoring the electrode 32 and manipulating the devicessuch that a strong near-field ventricular EGM signal is continuallydetected by the electrode 32. In another alternative, if no externalelectrode 32 is provided on the capture device 20, an operator could,for example, monitor the electrodes 34 and 36 on both jaws of thecapture device 20 to determine whether the EGM signal detected from oneelectrode indicates that its jaw is located closer to the ventriculartissue than the other jaw (or that both jaws show an equal signalstrength indicating that both jaws are equally close to the ventriculartissue).

The typical EGM signal associated with a normal human heartbeat (orcardiac cycle) includes a P wave, a QRS complex and a T wave as depictedin FIG. 5. FIGS. 6A-6C depict the EGM signals that may be detected invarious locations over the heart. The differences in the EGM signals canbe used to determine the position of the electrodes (and thus thedevices carrying them) relative to the anatomy of the heart. In someinstances, it may be helpful to obtain an electrocardiogram (ECG) signal(using, e.g., surface electrodes as is known conventionally) in additionto the intracardiac EGM signals. The ECG signal may then potentially beused to assist in the navigation process (by, e.g., signal subtraction,etc.).

FIG. 6A represents a potential EGM signal at the initial access point ofthe sub-xiphoid approach near the apex of the heart. At the apex of theheart there will be a small or insignificant atrial EGM signal (P-wave)80 and a much more pronounced higher amplitude and strong ventricularsignal (QRS complex) 81. When the recording electrode is at the apex ofthe heart or near primarily ventricular tissue the P wave (atrialelectrical signal) 80 is much weaker and the QRS complex (ventricularelectrical signal) 81 is much stronger with higher amplitude on the EGMtracing.

FIG. 6B depicts a typical EGM tracing as an electrode approaches bothatrial and ventricular epicardial tissue. The P wave 82 in FIG. 6B has amuch larger amplitude as the electrodes come in contact with atrialtissue (i.e., larger than when the electrodes are at the apex of theheart as seen in FIG. 6A). The QRS complex 83 of FIG. 6B continues tohave a large amplitude due to continued contact with ventricular tissue.

FIG. 6C depicts the typical EGM tracing potentially seen usingelectrodes that are in contact with only atrial tissue such as, e.g.,the tissue of the left atrial appendage (which produces strong atrialEGM signals). The EGM signal of FIG. 6C shows a large amplitude P wave84 and a relatively small amplitude QRS complex signal 85. If thecapture device is in the form of a grasping apparatus including jaws,the electrodes that could produce the signal seen in FIG. 6C may be onopposing sides of the left atrial appendage, with the left atrialappendage tissue captured between the jaws. In such an arrangement,capture of electrically active tissue (such as the left atrialappendage) can be distinguished from the capture of electricallyinactive tissue (such as, e.g., the pericardium, epicardial fat pads,etc.) using the electrodes on the interior surfaces of the jaws.

Distinguishing between the different EGM signals may preferably beperformed by the operator (e.g., the physician), although, in somesystems and methods, the distinguishing may be performed with theassistance of an automated system that compares the detected EGM signalswith those associated with one or more desired outcomes.

FIG. 7 is another cross-sectional view of a human heart depicting theleft-side anatomy in which the navigation/capture system depicted inFIG. 4 is advanced further towards the left atrial appendage 54.Recording electrodes 34 and 36 on the capture device 20 are in directcontact with the epicardial surface of the left atrial appendage 54. Theelectrode 32 on the external surface of the capture device 20 is stillin contact with ventricular tissue.

As a result, the EGM signals detected from the external electrode 32would differ from the EGM signals detected using the internal electrodes34 and 36. The different EGM signals would provide a user with theability to determine that the capture device 20 had, in fact, capturedleft atrial appendage tissue. Left atrial appendage tissue is the firsttissue that produces an atrial EGM when approaching the left atrium fromthe apex of the heart through a sub-xiphoid access point.

The EGM signal detected between electrodes 34 and 36 would show a strongnear-field P wave with high amplitude (atrial electrical activity) and asmall amplitude QRS complex (ventricular electrical activity) asdepicted in FIG. 8A. In contrast, the external electrode 32 would show alarge amplitude QRS complex and potentially and either small or largeamplitude P wave depending on its contact with left atrial appendagetissue as depicted in FIG. 8B. It should be noted that the space betweenthe epicardial surface of the heart in the pericardial sac is often fullof fluid which may be electrically conductive and may distort the EGMsignal slightly when not in direct contact with myocardial tissue.

FIG. 7 provides an opportunity to visualize how the systems and methodsdescribed herein may allow the operator to navigate from the apex of theheart (where initial contact is with the epicardial surface during asub-xiphoid approach) to the tip of the left atrial appendage. As thedelivery device 10 (and associated capture device 20) advance across thesurface of the heart, the initial EGM signals will indicate contact withventricular tissue (see, e.g., FIG. 6A). The first EGM signal indicatingcontact with atrial tissue when approached from the apex of the heart(using, e.g., sub-xiphoid access) should be the tissue of the leftatrial appendage.

Further guidance to supplement the use of EGM signals during theprocedure may be obtained using other imaging/guidance modalities suchas, e.g. fluoroscopy, direct visualization, ultrasound imaging, MRIimaging, CT scans, etc. The use of a secondary imaging/guidancetechnique may be used to potentially confirm capture of the left atrialappendage by, e.g., providing information regarding the angle of closureof the jaws of a grasping apparatus, etc. If, for example, no tissue iscaptured, then the jaws of a grasping apparatus may close completely.When tissue is present, the jaws will typically not close completely.

FIG. 9 depicts a situation in which the capture device 20 (andassociated delivery device 10) of FIG. 4 is advanced towards the leftatrial appendage, but is closed without capturing the tissue of the leftatrial appendage. One potential benefit of using EGM signals to navigateto and/or confirm capture of the left atrial appendage tissue is thatwhen the electrodes on a capture device 20 close without capturingtissue between them, the EGM signal would not show a strong amplitude Pwave. Rather, the electrodes 34 and 36 would be expected to short outand show a flat line EGM signal as depicted in FIG. 10A because theelectrical potential across the electrodes 34 and 36 is zero. If theoperator only grabs a small portion of the left atrial appendage tissuein the capture device 20, there also may not be enough impedance, withthe result being, again, a flat line EGM signal as depicted in FIG. 10A.In this case, an operator could re-open the capture device 20 andreposition it until the electrodes 34 and 36 indicate a strong amplitudeP wave and corresponding contact with left atrial appendage tissue.

In the situation depicted in FIG. 9, the external electrode 32 on thecapture device 20 would typically be expected to show a large amplitudeQRS complex and potentially and either small or large amplitude P wavedepending on its contact with left atrial appendage tissue as depictedin FIG. 10B.

FIG. 11 depicts another situation in which the capture device 20 (andassociated delivery device 10) are advanced too far. When the capturedevice 20 is advanced past the tip of the left atrial appendage that isclosest the apex of the heart, it will likely not come into contact withany other atrial tissue. Any tissue that is captured by the capturedevice 20 as depicted in FIG. 11 will have an non-atrial EGM signal. Theelectrodes 34 and 36 on the capture device 20 may, for example, reflectan EGM signal of the pericardium or far-field ventricular and/or atrialsignals. The external electrode 32 on the capture device 20 may reflecta strong atrial EGM signal given that it may still be in contact withthe left atrial appendage as the capture device 20 passes over theappendage (which may be an indication that the capture device 20 isincorrectly positioned). When the LAA is properly positioned in thecapture device 20, the external electrode 32 should detect at least someventricular EGM signal as discussed herein.

FIG. 12 depicts another situation in which the capture device 20 (andassociated delivery device 10) are advanced into a position that is notamenable to proper capture of the left atrial appendage. In thissituation, the capture device 20 is depicted as advanced beneath the tipof the left atrial appendage, such that the capture device 20 is locatedbetween the left atrial appendage and the underlying ventricular tissue.In such an arrangement, it would be unlikely that the capture device 20could properly capture left atrial appendage tissue for a subsequentprocedure. Tissue that is captured when the capture device 20 is beyondthe position depicted in FIG. 12 could likely be ventricular tissue witha ventricular EGM signal across electrodes 34 and 36 on the capturedevice 20.

Confirmation of the situation depicted in FIG. 12 could potentially beobtained if the EGM signals from the electrodes 34 and 36 on the capturedevice showed both atrial and ventricular signatures as depicted in,e.g., FIG. 13A. In addition, the external electrode 32 may, if itlocated nearest the ventricular tissue, show an EGM signal weightedtowards the QRS complex portion of the complete EGM signal as depictedin FIG. 13B.

The situation depicted in FIG. 12 may not, however, be entirelyhopeless. The capture device 20 could potentially capture a lobe of theleft atrial appendage and this could be a clinically acceptable outcome.Confirmation of this outcome could potentially be obtained by, e.g.,detecting a strong atrial EGM signal (see, e.g., FIG. 6C) using theelectrodes 34 and 36 on the capture device 20.

FIG. 14 depicts another exemplary embodiment of a delivery device 310and a capture device 320 similar to those depicted in FIGS. 1 and 3.Unlike the devices in those figures, the electrodes 316 and 318 on thedelivery device 310 and the electrodes 332, 333, 334, and 335 on thecapture device 320 are all ring electrodes. The ring electrodes 316 and318 on the delivery device 310 could, however, be used in conjunctionwith electrodes on the jaws 322 and 324 to improve navigation to theleft atrial appendage by potentially more precisely establishingposition of the distal ends of the jaws 322 and 324 of the capturedevice 320. Any or all of the electrodes could be monopolar ormultipolar.

The electrodes 316 and 318 on the delivery device 310 could be used bythe operator to help differentiate between the ventricular and atrialtissue as the delivery device 310 is advanced. Additional specificity ofEGM interpretation is potentially feasible with the electrodeconfiguration depicted in FIG. 14. For example, reading a bi-polarsignal across electrode 332 and 334 on jaw 322 or electrode 335 and 336on jaw 324 may allow the operator to better confirm the presence ofparticular types of tissue within the capture device 320 (i.e.,ventricular tissue versus atrial tissue).

The electrodes on the jaws 322 and 324 of the device depicted in FIG. 14may also create a near-field EGM. The near-field EGM signal may producea cleaner and easier to interpret EGM signal for determination of tissuetype. The ring electrodes 316 and 318 on the delivery device 310 couldbe used for navigation in the pericardial space in a similar manner asdescribed above for the device depicted in FIG. 3, yet with thepotential for a more precise near-field EGM created from the two ringelectrodes 316 and 318.

Another potential embodiment depicted in FIG. 15 includes ringelectrodes 416 and 418 on the delivery device 410. The electrodes 433,434, 436, and 437 on the internal surfaces of the jaws 422 and 424 couldbe used to help better navigate and position the capture device 420. Theexternal electrodes 432 and 435 on the external surfaces of the jaws 422and 424 could be used to differentiate tissue on the external surface ofthe jaws 422 and 424 from that in contact with the internal surfaces ofthe jaws. Electrodes 433 and 434 on jaw 422 and electrodes 436 and 437on jaw 424 only capture the near-field EGM signal on the internalgrasping surfaces of the jaws. External electrodes 432 and 435 may beused to determine the position of the capture device 420 relative to thepericardium, ventricular tissue underneath the LAA or any other tissue.Any or all of the electrodes could be monopolar or multipolar.

With the ability to differentiate tissue on the external surface versusthe internal surface of the capture device 420, the configuration ofelectrodes on the capture device 420 may provide additional specificityof EGM interpretation versus the configuration seen in the device ofFIG. 14. The ring electrodes 416 and 418 on the delivery device 410could again be used for navigation in the pericardial space in a similarmanner as described for similar arrangements herein (with the potentialfor a more precise near-field EGM read from the two ring electrodes 416and 418).

In addition to the examples described herein, navigation and tissuecapture systems described herein may be integrated into known tissuecapture systems. Examples of some potentially suitable tissue capturesystems including delivery devices and capture devices may be describedin U.S. Patent Application Publication No. US 2007/0073313 (Liddicoat etal.). One example (depicted in FIG. 16) of a capture device 520according to the principles described in Liddicoat et al. may, forexample, include electrodes 530 integrated with the supports or guidesincluded in the disclosed devices. The capture device 520 may preferablybe delivered using a delivery device 510. The system of FIG. 16 may alsoinclude an optional guide element 540 which may include an electrode 542in place of or in addition to a magnet as described in Liddicoat et al.If the guiding element 540 is provided with an electrode 542, theelectrodes 530 on the capture device 520 may be optional.

Yet another exemplary embodiment of a capture device 620 is depicted inFIG. 17 in the form of a catheter that includes a lumen that may be usedto provide suction to capture tissue. The capture device 620 may includeone or more electrodes 630 proximate (at or near) the distal end of thecatheter to detect physiological electrical activity to guide thecapture device as described herein. The capture device 620 may also (oralternatively) include one or more electrodes that are spaced from thedistal end of the capture device 620 as described herein with respectto, e.g., the embodiments depicted in FIGS. 18-20.

Still another exemplary embodiment of a capture device 720 that may beused in the systems and methods described herein is depicted inconnection with FIG. 18. The capture device 720 includes a first jaw 722and a second jaw 724. The first and second jaws 722 and 724 may bemounted on the distal end of a capture shaft 726 that can be used toadvance the capture device 720 through the lumen of an introducer,endoscope, catheter, trocar, etc. that can provide access to a selectedinternal body location.

The capture devices of systems and methods described herein maypreferably operate in an atraumatic manner to capture tissue. As usedherein, “atraumatic” (and variations thereof) means that the capturedevices described herein, when used to capture tissue, do not cut,sever, or remove the captured tissue. In other words, the capturedevices used in connection with the systems and methods described hereincan be distinguished from conventional biopsy devices because thecapture devices described herein preferably do not cut, sever, and/orremove of tissue as would conventional biopsy devices. The capturedevices may, however, include retention structures/features such asserrations, teeth, roughened surfaces, posts, pins, adhesives, etc. thatcontribute to the ability of the capture devices to maintain attachmentto tissue captured within the jaws while still remaining an atraumaticdevice.

In the depicted embodiment of the capture device 720, one example of aretention structure is found in the complementary teeth 727 found on thejaws 722 and 724. The depicted retention structure includes one tooth727 located on the first jaw 722 and two teeth 727 located on the secondjaw 724. The tooth 727 on jaw 722 may preferably nest within the pair ofteeth 727 to assist in retaining tissue within the capture device 720.

The first jaw 722 of capture device 720 has an interior surface 723 thatfaces the interior surface 725 of the opposing second jaw 724. Alsoincluded in the depicted embodiment of capture device 720 is a firstelectrode 732 positioned on the interior surface 723 of the first jaw722 and a second electrode 734 positioned on the interior surface 725 ofthe second jaw 724.

As described herein, the capture device 720 may have a closedconfiguration in which the jaws are closed such that the interiorsurfaces 723 and 725 of the first and second jaws 722 and 724 movetowards each other and an open configuration (see, e.g., FIG. 18) inwhich the first and second jaws are open and spaced apart such that thecapture device can capture tissue between the jaws 722 and 724.

The capture device may optionally include a mechanism to lock the jawsin the closed configuration such that a user is not required tocontinually hold the capture device 720 in the closed configuration. Thelocking mechanism may preferably be operable from the proximal end ofthe capture device. In one embodiment, the locking mechanism may takethe form of a biased (e.g., spring-loaded, etc.) mechanism that holdsthe jaws of the capture device in a closed configuration in the absenceof any intervening force that is applied to open the jaws. Such anembodiment may be referred to as having “normally-closed” jaws.

In still other embodiments, the jaws of a capture device mayalternatively be biased (e.g., spring-loaded, etc.) in an openconfiguration in the absence of an intervening force that is applied toclose the jaws. Such an embodiment may be referred to as having“normally-open” jaws. Such jaws may be closed to capture tissue usingany suitable mechanism including, but not limited to a sheath that canbe advanced distally over the jaws, thereby urging them into a closedconfiguration.

Referring to, e.g., FIG. 1 in addition to FIG. 18, the capture device720 may also have a delivery configuration in which the distal end ofthe capture device 720 (typically the jaws 722 and 724) is containedwithin the capture lumen of a delivery device such as a sheath,introducer, endoscope, catheter, trocar, etc. The capture device mayfurther have an extended configuration in which the distal end of thecapture device 720 extends out of the capture lumen of a delivery deviceproximate the distal end of the delivery device. This concept is alsodescribed above in connection with FIG. 1.

In the depicted embodiment, the jaws 722 and 724 are both attached forrotation about an axis 702 that is oriented generally transverse to alongitudinal axis 701 that extends from a proximal end to a distal endof the capture shaft 726. The axis of rotation 702 about which the jaws722 and 724 rotate may not necessarily be exactly transverse to thelongitudinal axis 701 in any or all planes that contain the longitudinalaxis 701.

Movement of the jaws 722 and 724 between the open and closedconfigurations can be accomplished by a wide variety of differentmechanisms. FIGS. 18-20 depict only one example of a potentiallysuitable mechanism. In the depicted embodiment, rotation of the jaws 722and 724 about the axis 702 means that the jaws 722 and 724 are pivotallymounted on a main rivet 740 that extends through arms 742 that extendfrom the capture shaft 726. Axis 702 (about which the jaws 722 and 724rotate) preferably extends through the main rivet 740.

Rotation of the jaws 722 and 724 about the axis 702 is effected in thedepicted embodiment by moving a link rivet 744 through slots 743 formedin arms 742. Movement of the link rivet 744 is effected, in the depictedembodiment, by moving an actuator such as a drive rod 741 through anactuator lumen in the capture shaft 726, with the link rivet 744 beingattached to the drive rod 741. The link rivet 744 also extends throughslots 745 and 747 located in the jaws 722 and 744. As the link rivet 744is advanced distally towards the distal end of the capture device 720(see, e.g., FIGS. 18 and 19), the jaws 722 and 724 open. Conversely, asthe drive rod 741 and attached link rivet 744 are moved proximally, thejaws 722 and 724 close (see, e.g., FIG. 20).

The capture device 720 also includes a variety of electrodes that can beused to monitor EGM signals. The depicted embodiment of the capturedevice 720 includes a first electrode 732 located on the interiorsurface 723 of the first jaw 722 and a second electrode 734 located onthe interior surface 725 of the second jaw 724.

A first electrode lead 733 extends from the first electrode 732 towardsa proximal end of the capture device 720. The first electrode lead 733is connected to the electrode 732, in the depicted embodiment, throughthe jaw 722 with a similar lead being located on the second jaw 724 (butnot depicted in FIGS. 18 and 19). The leads may preferably extendthrough the capture shaft 726 where they terminate at an EGM monitoringapparatus connector (not seen).

A potential alternative structure for electrically connecting theelectrodes 732 and 734 without using separate and discrete leads as seenin FIGS. 18 and 19 may include placing the main rivet 740 in electricalcommunication between a coil (other conductor) extending through thecapture shaft 726, the first jaw 722, and electrode 732. The main rivet740 is preferably electrically isolated from the second jaw 724 and itselectrode 734 by any suitable technique, e.g., insulating washers,bushings, etc. (which may be constructed of dielectric materials suchas, e.g., polyimides, PEEK, etc.). Similarly, the link rivet 744 mayserve as the path for electrical communication between another lead(such as the drive rod 741), the second jaw 724, and electrode 734. Thelink rivet 744 may also be electrically isolated from the first jaw 722and its electrode 732 by any suitable technique, e.g., insulatingwashers, bushings, etc. (which may be constructed of dielectricmaterials such as, e.g., polyimides, PEEK, etc.).

Although the jaws 722 and 724 may be made of electrically conductivematerials (such as, e.g., metals, etc.), they may be coated withnonconductive materials such that, e.g., the electrodes 732 and 734 onselected surfaces, e.g., the outer surfaces, etc. Some potentiallysuitable nonconductive materials may include polymers, paints, epoxies,etc. Insulating the outer surfaces and other areas of the capturedevices may potentially enhance the ability of the system to captureand/or distinguish EGM signals of tissue located within the capturedevice.

The electrodes 732 and 734 may, in some embodiments, be located on theinterior surfaces 723 and 725 of the jaws 722 and 724 such that theelectrodes are located opposite from each other. In such aconfiguration, closure of the jaws 722 and 724 in the absence of tissueor other material located therein may preferably result in electricalcommunication between the electrodes, e.g., the electrodes 732 and 734may “short out” when the jaws 722 and 724 are closed. Such an event maybe useful for providing an indication to a user that not tissue has beencaptured by the capture device 720.

Another optional feature that may be described in connection with theembodiment of the capture device 720 depicted in FIGS. 18 and 19 is thatthe electrodes used on the jaws of the capture device 720 may occupysubstantial portions of the interior surfaces of the jaws. For example,it may be preferred that the electrodes 732 and/or 734 occupy about onequarter or more of the interior surfaces 723 and 725 of the jaws. Insome embodiments, it may be further preferred that at least one of theelectrodes provided on the interior surface of a jaw occupy about onehalf or more of the interior surface of the jaw.

Although the capture device 720 includes a pair of electrodes, with oneelectrode located on each jaw, it should be understood that that manydifferent electrode configurations are possible. For example, only oneelectrode may be provided such that, e.g., only one of the jaws carriesan electrode (with a return electrode located elsewhere).

In another example, two or more electrodes may be placed on one jaw,while the other jaw contains no electrodes. The two or more electrodesmay be provided in any suitable configuration, e.g., they may bearranged along a straight line, in a circle, randomly, etc. An exampleof an embodiment in which only one of the jaws carries electrodes may beseen with reference to FIG. 15 where the capture device 420 may beprovided with only one set of interior electrodes (e.g., only electrodes433 and 434, but not electrodes 436 and 437). In such an embodiment, theopposing interior surface of the opposing jaw may be electricallyconductive such that closure of the jaws places the two electrodes inelectrical communication with each other (i.e., shorts out theelectrodes) to provide an indication that no tissue is captured betweenthe jaws. The electrically conductive interior surface may be inherentin the opposing jaw (if, e.g., the interior surface was exposed metal orsome other conductive material) or the opposing interior surface may beprovided with a conductive element on its interior surface that isplaced to provide the desired shorting out function.

Still another optional feature depicted in connection with, e.g., thecapture device 720 depicted in FIGS. 18-20 is the use of electrodes onthe capture shaft 726. As seen in FIGS. 18 and 19, the capture shaft 726includes a pair of shaft electrodes 736 and 738. The shaft electrodes736 and 738 may be used to, e.g., monitor the type of tissue in contactwith the shaft 726. As discussed herein, the EGM signals picked up byelectrodes used with the capture devices described herein can be usefulin determining the location of the device within, e.g., the pericardialspace. For example, the shaft electrode(s) 726 may potentially be usedin the same manner as the external electrodes on capture devicesdescribed in connection with FIGS. 4-13.

The shaft electrodes 736 and 738 may or may not be provided in the formof ring electrodes that extend around the perimeter of the shaft 726.The electrodes 736 and 738 may preferably be electrically isolated fromthe remainder of the capture device 720 and be placed in electricalcommunication with EGM monitoring apparatus through leads that extendproximally through the capture shaft 726.

Although two shaft electrodes 736 and 738 are depicted in connectionwith the capture device 720, the capture devices may be provided withonly one shaft electrode, three or more shaft electrodes, and even noshaft electrodes. If provided, the one or more shaft electrodes maypreferably be located within a distance of about 10 centimeters (cm) orless, about 5 cm or less, or even about 2 cm or less from the distal endof the capture device such that the EGM signals detected using the shaftelectrodes are those that are indicative of the tissue proximate theworking portion of the capture device.

The function of the shaft electrodes may, in some instances be providedand/or supplemented by using one or more electrodes at other locations,e.g., electrodes located on a delivery device used to deliver thecapture device, electrodes on exterior surfaces of the jaws or any otherelement of any other capture device, electrodes on the skin or at otherlocations on the subject, etc.

Although the capture devices depicted in FIGS. 18-20 and elsewhereherein include two jaws, both of which may be moved to change between anopen and closed configuration, it should be understood that the captureddevices may include more than two jaws, e.g., three, four or more jaws.In still other variations, one or more of the jaws may be stationerywhile one or more of the remaining jaws moves to changed between theopen and closed configurations. For example, with respect to theembodiment of FIGS. 18-20, the jaw 722 may be stationary with respect tothe capture shaft 726, while jaw 724 rotates to move the capture devicebetween the open and closed configurations.

As described herein, other navigation techniques may be used incombination with EGM-based navigation. An exemplary embodiment of anadditional method of navigating a device to an anatomical structure(e.g., the left atrial appendage) may include delivering a device intoan anatomical space (e.g., the pericardial sac); injecting imageenhancement liquid (e.g., a liquid contrast agent in the case offluoroscopy, echogenic liquids for use in conjunction with ultrasonicimaging, etc.) into the anatomical space (e.g., the pericardial sac);and identifying the location of the device and/or the locations ofanatomical structures (e.g., the left atrial appendage) using anyappropriate imaging modality, e.g., fluoroscopic visualization, MRI, CTscanning, etc. In some embodiments, this method and apparatus used toperform it could be used alone, i.e., without the aid of EGM-basednavigation.

Although this method of navigating a device to an anatomical structuremay be utilized for many anatomical structures (e.g., any structurerelating to the epicardial surface of the heart such as various veinsand arteries, fat pads, structural defects, etc.), the followingdescription, for simplicity, describes the use of the method and devicefor navigating to and/or outlining the left atrial appendage (LAA).

FIG. 21A depicts an exemplary device 800 injecting image enhancementliquid 810 into the pericardial sac to outline the LAA. The device 800,as depicted, includes an image enhancement liquid catheter 802. At leastin one embodiment, an approach for using this technology may be viapercutaneous access to the pericardial space gained using a subxiphoidapproach. In other embodiments, any approach to the epicardial surfaceof the heart may be utilized, including, e.g., thoracoscopic or otherpercutaneous approaches.

As shown in FIG. 21B, the image enhancement liquid delivered into thepericardial sac fills the voids between the LAA and the epicardialsurface of the heart, surrounding the structure to, e.g., outline theLAA under fluoroscopic imaging, etc. The ability to obtain a usefulimage may, in some embodiments, be directly related to the amount ofimage enhancement liquid in the imaging field. When used as describedherein in connection with the LAA, for example, the image enhancementliquid agent may fill the valleys created at the interface between theleft atrial appendage and the surrounding epicardial surface. Suchvalleys may have more image enhancement liquid “pooled” therein than isfound outside of the valleys and, as a result, typically appeardarkened, shadowed or be otherwise visible on the image. When theappendage moves through natural motion or is manipulated by an externaltool, the “valleys” may shift, which may increase the visibility of theLAA. The image enhancement liquid may be described as outlining theanatomical feature (e.g., the LAA).

Image enhancement liquids such as, e.g., contrast agents used inconnection with fluoroscopy, may be injected into the circulatory systemin conventional uses. Due to the nature of the circulatory system (e.g.,moving blood), operators typically only see the contrast for a fewseconds before it is diluted into the rest of the circulatory system.Liquid contrast agent (or another image enhancement liquid) that isinjected into the pericardial space, however, may naturally “pool” sincefluid does not flow into or out of the pericardial sac at a ratesufficient to remove or dilute the image enhancement liquid before itcan be used for imaging as described herein. As a result, injectingimage enhancement liquid into the pericardial space may allowvisualization of the pericardial space longer than, e.g., standardliquid contrast agent injections into the intravascular system (e.g.,five minutes or more).

Further, image enhancement liquid outlining may also be used with asecondary imaging modality to indicate to an operator how far a medicaldevice has been advanced within an anatomical area. Upon advancing adevice (e.g., a needle) into tissue, an operator may inject a smallamount of image enhancement liquid through the needle. Pooling of theimage enhancement liquid at the tip of the needle may indicate that thetip of the device is still located within surrounding tissue.Alternately, image enhancement liquid that disperses may indicate thatthe delivery port of the device has advanced into the intended openanatomical space. When used as described herein, the image enhancementliquid may preferably create a shadow outline of selected anatomicalstructure (e.g., the LAA located in pericardial sac between theepicardial surface and the inner surface of the pericardial sac).

Further, in at least one embodiment, near field or localized imageenhancement liquid injection may be used (e.g., about 1 cm or less fromthe LAA). Near field or localized image enhancement liquid injection maybe realized by injection through a small lumen so as to reduce theamount of image enhancement liquid needed and such that the imageenhancement liquid exits the nozzle in a jet or stream as opposed to aspray. Such near field or localized image enhancement liquid injectionmay be utilized because image enhancement liquid through a spray maydisperse evenly over a large area (which may not reveal any anatomicalstructures) as opposed to a smaller, localized area.

Still further, in at least one embodiment, image enhancement liquid maybe aspirated as necessary to maintain a more constant image of theenhanced image of the anatomical structure.

The image enhancement liquid may be injected according to the methodsdescribed herein utilizing any medical device, such as, e.g., acatheter, an introducer sheath, an electrical mapping catheter, anablation catheter, a grasper, an epicardial lead, a tissue ligationdevice, a drug delivery catheter, a syringe, etc. The device may have afixed curve or deflectable distal end in order to better navigate to ananatomical structure, e.g., the left atrial appendage.

For example, a cross-sectional view of an exemplary sheath introducer900 including a image enhancement liquid injection lumen 902 and deviceintroduction lumen 904 is depicted in FIG. 22A. Further, for example, across-section view of another exemplary sheath introducer 910 includingmultiple image enhancement liquid injection lumens 912 and deviceintroduction lumen 914 is depicted in FIG. 22B.

Still further, for example, an exemplary capture device 920 includingmultiple image enhancement liquid injection lumens 922 is depicted inFIG. 23A. Yet still further, for example, another exemplary capturedevice 930 including a image enhancement liquid injection lumen 932 isdepicted in FIG. 23B.

At least in one embodiment, the device may include a bladder or chamberfor holding image enhancement liquid. The bladder or chamber may beintegral with the device or may be a separate device. For example, adevice may include a port for receiving a cartridge or other containerhaving image enhancement liquid therein, with the port being in fluidcommunication with a lumen used to deliver the image enhancement liquidinto the pericardial space.

At least in another embodiment, the device may include an automatic pumpthat may inject the image enhancement liquid. The automatic pump mayoperable to control the frequency, flow rate, concentration, pressure,etc. Further, a user may adjust any parameter that the automatic pumpmay control to achieve the desired result from the image enhancementliquid injection. In at least one embodiment, the automatic pump maydeliver image enhancement liquid for, e.g., 1 second every 2 minutes.

At least in still another embodiment, a kit may be provided thatincludes a device for injecting image enhancement liquid as well as anyother medical device that may be utilized in conjunction withfluoroscopic imaging. For example, a kit may include a tissue ligationdevice, a image enhancement liquid injection device, an introducersheath, syringe, an automated pump, etc. Other components that mayoptionally be included as a part of such a kit may include, e.g., acontainer or cartridge of image enhancement liquid, etc.

Although FIGS. 22A, 22B, 23A, and 23B only depict a few configurationsof a medical device utilizing image enhancement liquid injectioncatheters, image enhancement liquid injections catheters may be utilizedas a part of or in conjunction with any medical device described herein.

FIG. 24 depicts one embodiment of a system that may include one or morecapture devices in combination with a ligation device, with both devicesbeing delivered through the same delivery device. In particular, theembodiment depicted in FIG. 24 includes a delivery device 1010 havingone or more lumens formed therethrough. The delivery device 1010 may bein the form of a sheath, introducer, catheter, trocar, endoscope, etc. Acapture device 1020 is depicted as being delivered through the lumen1012 of the delivery device 1010, with the capture device 1020 beingdelivered on a capture shaft 1026. A ligation device 1030 is alsodelivered through the lumen 1012, the depicted ligation device 1030being in the form of a loop delivered on a shaft 1032.

It may be preferred that the capture device 1020 be directed through theloop of the ligation device 1030 such that captured tissue couldpotentially be drawn proximally through the loop (or the loop advanceddistally over the tissue) to facilitate ligation of the tissue using theloop. Examples of some potentially useful ligation devices that could beused in this manner may include those described in, e.g., U.S. Pat. No.5,865,791 to Whayne et al.; International Publication WO 2008/036408 A2,titled DEVICES AND METHODS FOR LIGATING ANATOMICAL STRUCTURES; U.S. Pat.No. 6,488,689 to Kaplan et al., etc.

Another system level schematic is depicted in FIG. 25 to show potentialconnections between electrodes and other components that may be usedwith tissue navigation and capture systems described herein. Thedepicted system includes a capture device 1120 having one or moreelectrodes 1130 and connector 1140 connected to the electrodes 1130through leads 1131. The depicted system also includes a delivery device1110 that may include an electrode 1132 (or more than one electrode) anda connector 1142 connected to the electrode 1132 through a lead 1133.

The connectors 1140 and 1142 may be adapted to connect to an electrical(e.g., EGM, etc.) monitoring device 1100 through connectors 1150 and1152. As a result, innate electrical signals that may be detected by theelectrodes may be monitored, displayed, etc. to assist a user innavigating the delivery device and/or capture device as describedherein. The connectors may take any suitable form, e.g., plugs, sockets,bare wires, snap-fit connectors, etc.

Among variations that may or may not be explicitly described herein, thefollowing features, components, etc. may be included in the navigationand tissue capture systems described herein. For example, although thedevices are depicted as having substantially straight bodies, they maybe precurved such that in the absence of an intervening force, thebodies take on a curved shape.

The systems and methods described herein could be used to detect tissuesother than the left atrial appendage using other detectablephysiological electrical activity that can provide guidance fornavigation.

The systems and methods described herein may be used in a manualoperation, i.e., where one or more operators manually position thedevices described herein. Alternatively, some or all of the devices inthe systems and methods described herein may be controlled by automatedequipment (e.g., robotically, etc.).

The systems and methods described herein could be used in conjunctionwith the following surgical techniques: laparascopic, keyhole, NaturalOrifice Transluminal Endoscopic Surgery (NOTES), open surgery,endoscopic surgery, etc. and combinations of two or more of thesetechniques.

Although described in connection with the human anatomy, the systems andmethods described herein could be used with any animal (i.e., have usein both human and veterinary applications).

Although not explicitly depicted, the EGM detection can be performedbetween any two electrodes or between a single electrode and ground(electrically neutral). Ground can be created by, e.g., placing a patchelectrode on a subject's body (or placing another electrode on or on thebody) and using it as a reference electrode.

FIGS. 26-35 depict alternative electrode configurations and placementsfor use in navigation and tissue capture systems. With respect to FIG.26, the depicted system includes a delivery device 1210 that includes anexpansion device 1280 delivered into a selected internal body location(e.g., the pericardial space). In the depicted embodiment, the expansiondevice 1280 is in the form of an expandable balloon that is deliveredthrough a lumen 1284 in the delivery device 1210. The expansion device1280 may include one or more electrodes 1282 on its surface (thedepicted embodiment includes three electrodes 1282). The electrodes 1282may preferably be operably connected to one or more leads that extendproximally back through the delivery device 1210 to connect tomonitoring apparatus as described herein. The electrodes 1282 can beused to detect innate electrical activity such as EGM signals to assistin navigation of the delivery device 1210 and/or tissue capture asdescribed herein. Similar devices (not including electrodes fornavigation) may be described in more detail in U.S. Pat. No. 6,488,689to Kaplan et al.

The system depicted in FIG. 27 includes a ligation element 1380 that mayinclude one or more electrodes 1382 carried on the ligation element1380. The ligation element 1380 can be delivered through a deliverydevice 1310 and the ends of the ligation element can be manipulated toadjust the size of the loop formed by the ligation element 1380. Theelectrodes 1382 may preferably be operably connected to one or moreleads that extend proximally back through the ligation element 1380 toconnect to monitoring apparatus as described herein. Similar devices(not including electrodes for navigation) may be described in moredetail in U.S. Patent Application Publication No. 2008/0294175 toBardsley et al.

The system depicted in FIG. 28 includes a ligation element 1480 that mayinclude one or more electrodes 1482 carried on the ligation element1480. The ligation element 1480 can also be delivered through a deliverydevice 1410. The electrodes 1482 may preferably be operably connected toone or more leads that extend proximally back through the ligationelement 1480 to connect to monitoring apparatus as described herein.Similar devices (not including electrodes for navigation) may bedescribed in more detail in U.S. Patent Application Publication No.2008/0294175 to Bardsley et al.

The system depicted in FIGS. 29A and 29B includes a delivery device 1510that is used to deliver a capture device including two capture elements1522 and 1524. The capture elements 1522 and 1524 are moved into aclosed position with respect to each other by advancing a sleeve 1526 inthe distal direction. The delivery device also includes a ligationelement 1580 that extends through the delivery device 1510 and that isheld at the ends of coiled delivery arms 1584 that also extend throughthe delivery device 1510. The delivery arms 1584 also include electrodes1582. The electrodes 1582 may preferably be operably connected to one ormore leads that extend proximally back through the delivery device 1510to connect to monitoring apparatus as described herein. The system ofFIGS. 29A and 29B also includes an electrode 1536 on the delivery device1510. Although not depicted, the capture elements 1522 and 1524 mayinclude electrodes as described for capture devices herein. Similardevices (not including electrodes for navigation) may be described inmore detail in U.S. Patent Application Publication No. 2008/0294175 toBardsley et al.

The system depicted in FIGS. 30 and 31 includes a delivery device 1610extending from a handle 1602. The delivery device 1610 includeselectrodes 1682 that, in the depicted embodiment, are located proximatethe distal end of the delivery device 1610. The depicted delivery deviceincludes lumens 1612, 1614, and 1616 that can be used to deliver devicesand/or other materials. The electrodes 1682 may preferably be operablyconnected to one or more leads that extend proximally back through thedelivery device 1610 to connect to monitoring apparatus as describedherein. Similar devices (not including electrodes for navigation) may bedescribed in more detail in U.S. Pat. No. 6,488,689 to Kaplan et al.

The system depicted in FIG. 32 includes another embodiment of a deliverydevice 1700 extending into an internal space through tissue and includeselectrodes 1782 on its distal end. The electrodes 1782 may preferably beoperably connected to one or more leads that extend proximally backthrough the delivery device 1700 to connect to monitoring apparatus asdescribed herein. Similar devices (not including electrodes fornavigation) may be described in more detail in U.S. Pat. No. 6,488,689to Kaplan et al.

The system depicted in FIGS. 33A, 33B, and 33C includes a deliverydevice 1810 that is used to deliver a capture device 1820 in the form ofa clip. The capture element 1820 is moved into position over theselected tissue (e.g., the left atrial appendage) by advancing the clip1820 through a lumen in the delivery device 1810 using a capture shaft1826. The clip 1820 in the depicted embodiment includes electrodes 1882.The electrodes 1882 may preferably be operably connected to one or moreleads that extend proximally back through the delivery device 1810 toconnect to monitoring apparatus as described herein. The system asdepicted in FIG. 33A shows the clip 1820 being advanced over the leftatrial appendage using the delivery device 1810. FIG. 33B depicts theclip 1820 after deployment, with the delivery device 1810 still inposition. FIG. 33C depicts the clip 1820 deployed and the deliverydevice removed. Similar devices (not including electrodes fornavigation) may be described in more detail in U.S. Pat. No. 6,488,689to Kaplan et al.

The system depicted in FIG. 34 includes another embodiment of a deliverydevice 1910 used to deliver a ligation element 1980 that includes ahandle 1900 at its proximal end, the handle 1900 including an actuator1902 that may be used to adjust the size of the loop of the ligationelement 1980. The ligation element carries electrodes 1982 that maypreferably be operably connected to one or more leads that extendproximally back through the delivery device 1910 to connect tomonitoring apparatus as described herein. Similar devices (not includingelectrodes for navigation) may be described in more detail in U.S.Patent Application Publication No. 2008/0243183 to Miller et al.

With respect to FIG. 35, the depicted system includes a delivery device2010 that includes an expansion device 2080 delivered into a selectedinternal body location (e.g., the pericardial space). In the depictedembodiment, the expansion device 2080 is in the form of an expandablecage. The expansion device 2080 may include one or more electrodes 2082(the depicted embodiment includes four electrodes 1282). The electrodes2082 may preferably be operably connected to one or more leads thatextend proximally back through the delivery device 2010 to connect tomonitoring apparatus as described herein. The electrodes 2082 can beused to detect innate electrical activity such as EGM signals to assistin navigation of the delivery device 2010 and/or tissue capture asdescribed herein. Similar devices (not including electrodes fornavigation) may be described in more detail in U.S. Patent ApplicationPublication No. 2008/0294175 to Bardsley et al.

Other Considerations with Respect to Navigation

Sensed Electrograms:

When a solitary ventricular electrogram is sensed, the capture and/ordelivery device is manipulated in a cephalad direction towards thetypically located left atrial appendage or left atrium. If, on furtheradvancement, both ventricular and atrial electrograms are noted, thenthe tip of the device is either between the overlying left atrialappendage and the underlying left ventricular myocardium (betweenappendage and LV), or on the mitral annulus. To further distinguishthese two possibilities the following may be noted.

First: An equally near field atrial and ventricular electrogram despitemovement in a cephalad—caudad direction suggests location between theoverlying appendage and the left ventricular myocardium. Whereas, whensuch movements results in either a larger—more near field atrialelectrogram or a larger—more near field ventricular electrogram—locationalong the annulus is suggested.

Second: Flexion of the device so as to rotate the tip of the device awayfrom the myocardium and towards the epicardium results in a continuedsensed near field signal, which is now a larger atrial electrogram.Would diagnose location between the appendage and the ventricle. On theother hand, if such a movement results in loss of near field signalslocation along the annulus with now loss of contact with deflection ofthe catheter towards the epicardium is suggested.

If on further advancement in a cephalad direction results in only anatrial electrogram being identified, then the device is over the leftatrial appendage or has advanced over the posterior leftatrium/pulmonary veins. To make the distinction between thesepossibilities the device is moved in a septal direction (towards thepulmonary artery). With such movement if atrial electrograms arecontinued to be seen despite movement of more then 3 cm the initiallocation was likely over the posterior left atrium. However, if minimalseptal movement results in loss of the atrial electrogram with either nosignificant electrograms being recorded or only a far field ventricularelectrogram, then location overlying the left atrial appendage issuggested.

Further diagnostic information that facilitates the mapping with theelectrical navigation system may be based on the differences betweenelectrograms detected between the “jaws” of the device, closely spacedbipolar electrograms and more widely spaced electrograms—for example,with the cathode on the jaw and the anode on the shaft of the catheter.If, for example, both atrial and ventricular electrograms are seen inthe widely spaced bipolar configuration but only near field atrialelectrograms are seen in the closely spaced bipole distally located onthe tip of the device, then the tip is likely on atrial tissue (leftatrial appendage) where as the shaft remains at the junction between theappendage and the left ventricle. After deployment of the jaws (graspingtissue) if solely recorded near field electrograms are seen, grasping ofatrial tissue is confirmed. On the other hand, if the widely spacedelectrode configuration detects atrial electrograms but upon deploymentof the grasper—now no electrograms are seen, it is likely that thedevice was on the atrium/appendage but pericardial or other tissue hasbeen grasped by the device.

Pacing Stimulation:

Stimulation to pace and capture proximate myocardial tissue is performedboth in a widely spaced bipolar configuration and in a closely spacedbipolar configuration—for example, between the jaws of the grasper andin some instances in a unipolar configuration. If pacing stimulationresults in simultaneous atrial and ventricular capture, then either anannular location or location of the catheter between the appendage andthe left ventricular myocardium is likely. The situation can beclarified by advancing and withdrawing the device with continued pacing.If persistent simultaneous atrial and ventricular capture is seen,position between the appendage and LV myocardium is likely. Whereas withadvancement of atrial capture occurs and on the drawing ventricular onlycapture occurs, the tip of the device is likely on the mitral annuls.

If an atrial electrogram was sensed on the distal electrodes of thedevice and the grasper deployed, pacing stimulation is now attemptedfirst as soon as tissue is grasped. If atrial capture does not occurthen pericardial, adipose or other tissues has likely been grasped andthe device is redeployed. If atrial capture occurs then the graspedtissue is withdrawn into the sheath and pacing stimulation reattempted.If atrial capture is still confirmed then the atrial appendage beinggrasped is confirmed.

If only atrial capture occurs from the distal bipolar electrodes but ondeploying the grasper no atrial electrograms are seen on the jawelectrodes (despite atrial capture from the distal electrodes or awidely spaced electrode configuration) then left atrial tissue, atrialto the annulus but not over the left atrial appendage is likely and thedevice repositioned.

Arrhythmia During Device Navigation and Capture

If capture is confirmed with electrograms and pacing is noted above ofleft atrial appendage tissue, a ligation device is deployed. Ontightening the ligature or other grasping device atrial fibrillation isnoted then appendage manipulation and tightening of the ligature islikely. If on further tightening the ligature or the larger graspingdevice, the atrial fibrillation or other atrial arrhythmia is no longerseen, the a secure ligature etc. has been placed.

Variations of Electrogram Mapping Technique in Atrial Fibrillation

When the patient is in atrial fibrillation, sensed fibrillatory wavessubplant the atrial electrogram in the descriptions above. For example,simultaneous detection of fibrillatory waves and near field ventricularelectrograms would suggest deployment of the device between theappendage and overlying myocardial surface. If only fibrillatory waveelectrograms are seen, the device is manipulated further cephalad. Ifthis results in minimal fluoroscopic movements but continued sensedfibrillatory waves appendage location is likely. Pacing maneuvers toconfirm appendage location would not be used during atrial fibrillation,however the presence of ventricular capture or phrenic nerve capture onthe distal closely spaced bipolar shaft electrodes or jaw electrodesafter the grasper has been deployed would preclude further interventionssuch as placing a snare or ligature over the electrical mapping devicebut rather result in redeployment of the angle for orientation of thedevice to repeat the electrogram based mapping technique.

Automated or Partially Automated Electrical Navigation

In some iterations the deflection of the sheath or grasper or whenremotely steered, the target electrogram (sequence of initialventricular electrogram followed by simultaneous atrial and ventricularelectrograms followed by predominant atrial electrograms) will determinewhether movement or flexion of the device occurs. That is, by anautomated test movement of a few mm the atrial electrogram becomesmaller or less near field, then the device will no longer move or bedeflected in that direction (moving away from the atrium) etc. Byrepetitive test movements using the criteria described above with bothpacing stimulation and the sensed electrogram an automatic or partialautomatic deployment towards the appendage occurs.

The complete disclosure of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated.

Exemplary embodiments of navigation and tissue capture systems andmethods have been discussed and reference has been made to possiblevariations. These and other variations and modifications will beapparent to those skilled in the art without departing from the scope ofthe invention, and it should be understood that the invention is notlimited to the illustrative embodiments set forth herein. Accordingly,the invention is to be limited only by the claims provided below andequivalents thereof.

The invention claimed is:
 1. A method of navigating a device to a leftatrial appendage, the method comprising: delivering a capture device ona capture shaft into a pericardial sac, wherein the capture devicecomprises a first jaw and a second jaw, wherein each of the first jawand the second jaw comprises an interior surface, wherein the first jawand the second jaw comprise an open configuration in which the first jawand the second jaw are open and a closed configuration in which thefirst jaw and the second jaw are closed, wherein the interior surface ofthe first jaw is located closer to the interior surface of the secondjaw when the first jaw and the second jaw are in the closedconfiguration than when the first jaw and the second jaw are in the openconfiguration, and wherein a first electrode is located on the internalsurface of the first jaw and a second electrode is located on theinternal surface of the second jaw; moving the first jaw and the secondjaw from the open configuration to the closed configuration afterdelivering the capture device into the pericardial sac, wherein movingthe first jaw and the second jaw captures a left atrial appendagebetween the first jaw and the second jaw; detecting an EGM signal usingthe first electrode on the first jaw and the second electrode on thesecond jaw of the capture device after moving the first jaw and thesecond jaw from the open configuration to the closed configuration tocapture the left atrial appendage within the pericardial sac andconfirming capture of the left atrial appendage by the capture device bydetermining if the EGM signal is associated with tissue of the leftatrial appendage; wherein delivering the capture device on the captureshaft into the pericardial sac comprises advancing the capture deviceover ventricular myocardium tissue before the capture device reaches theleft atrial appendage, detecting a capture shaft EGM signal using acapture shaft electrode located on the capture shaft proximal from thecapture device, and confirming that the capture shaft electrode iscontacting ventricular tissue using the capture shaft EGM signal.
 2. Amethod of navigating a device to the left atrial appendage according toclaim 1, the method further comprising confirming capture of atrialtissue by the capture device by electrically stimulating the atrialtissue and confirming that the atrial tissue is being paced.
 3. A methodof navigating a device to the left atrial appendage according to claim1, the method further comprising determining that the left atrialappendage is not captured between the first jaw and the second jaw ifthe EGM signal is not associated with tissue of the left atrialappendage.
 4. A method of navigating a device to the left atrialappendage according to claim 1, wherein the first jaw and the second jawcomprise atraumatic nesting retention structure located at distal endsof each of the first jaw and the second jaw, wherein proximal ends ofeach of the first jaw and the second jaw are located between the distalends of the first jaw and the second jaw and a distal end of the captureshaft; wherein moving the first jaw and the second haw to the closedconfiguration comprises atraumatically capturing tissue in theatraumatic nesting retention structure.
 5. A method of navigating adevice to the left atrial appendage according to claim 4, wherein thefirst electrode is located proximally from the atraumatic nestingstructure, and wherein the atraumatic nesting retention structure doesnot form a part of the first electrode.
 6. A method according to claim1, wherein the capture device is delivered to the pericardial sac in anapproach that enters the pericardial sac through an opening formed inthe pericardial sac and that does not pass through the rib cage.
 7. Amethod according to claim 1, the method further comprising: injectingimage enhancement liquid into the pericardial sac; and whereindelivering the capture device into the pericardial sac comprisesadvancing the capture device in the pericardial sac using a visual imageobtained after injecting image enhancement fluid into the pericardialsac.
 8. A method according to claim 7, wherein the image enhancementfluid comprises a fluoroscopic contrast agent and the visual imagecomprises a fluoroscopic image.
 9. A method of navigating a capturedevice to a left atrial appendage, the method comprising: delivering acapture device on a capture shaft into a pericardial sac, wherein thecapture device comprises a first jaw and a second jaw comprising an openconfiguration in which the first jaw and the second jaw are open and aclosed configuration in which the first jaw and the second jaw areclosed, wherein an interior surface of the first jaw is located closerto an interior surface of the second jaw when the first jaw and thesecond jaw are in the closed configuration than when the first jaw andthe second jaw are in the open configuration; moving the first jaw andthe second jaw from the open configuration to the closed configurationafter delivering the capture device into the pericardial sac, whereinmoving the first jaw and the second jaw captures a left atrial appendagebetween the first jaw and the second jaw; detecting an electrical signalin the pericardial sac using an electrode on the capture device aftermoving the first jaw and the second jaw from the open configuration tothe closed configuration to capture the left atrial appendage;confirming capture of the left atrial appendage by the capture deviceafter moving the first jaw and the second jaw from the openconfiguration to the closed configuration to capture the left atrialappendage by determining if the electrical signal is associated withelectrical signals generated by tissue of the left atrial appendages;wherein delivering the capture device on the capture shaft into thepericardial sac comprises advancing the capture device over ventricularmyocardium tissue before the capture device reaches the left atrialappendage, detecting a capture shaft EGM signal using a capture shaftelectrode located on the capture shaft proximal from the capture device,and confirming that the capture shaft electrode is contactingventricular tissue using the capture shaft EGM signal.
 10. A methodaccording to claim 9, the method further comprising confirming captureof atrial tissue by the capture device by electrically stimulating theatrial tissue using the electrode on the capture device and confirmingthat the atrial tissue is being paced.
 11. A method according to claim9, wherein the electrode on the capture device comprises a firstelectrode on the first jaw and a second electrode on the second jaw, andwherein detecting the electrical signal comprises detecting theelectrical signal using the first electrode and the second electrode.12. A method according to claim 11, wherein the method further comprisesdetermining that the left atrial appendage is not captured between thefirst jaw and the second jaw if the electrical signal is not associatedwith tissue of the left atrial appendage.
 13. A method according toclaim 9, wherein the capture device comprises atraumatic nestingretention structure that comprises structure located at a distal end ofthe first jaw and structure located at a distal end of the second jaw,wherein a proximal end of the first jaw is located between the distalend of the first jaw and the distal end of the capture shaft, andwherein a proximal end of the second jaw is located between the distalend of the second jaw and a distal end of the capture shaft; whereinmoving the first jaw and the second jaw to the closed configurationcomprises atraumatically capturing tissue in the atraumatic nestingretention structure.
 14. A method according to claim 13, wherein theelectrode on the capture device is located proximally from theatraumatic nesting structure such that the atraumatic nesting retentionstructure does not form a part of the electrode.
 15. A method accordingto claim 9, wherein the capture device is delivered to the pericardialsac in an approach that enters the pericardial sac through an openingformed in the pericardial sac and that does not pass through the ribcage.
 16. A method according to claim 9, the method further comprising:injecting image enhancement liquid into the pericardial sac; and whereindelivering the capture device into the pericardial sac comprisesadvancing the capture device in the pericardial sac using a visual imageobtained after injecting image enhancement fluid into the pericardialsac.
 17. A method according to claim 16, wherein the image enhancementfluid comprises a fluoroscopic contrast agent and the visual imagecomprises a fluoroscopic image.
 18. A method of navigating a device to aleft atrial appendage, the method comprising: delivering a capturedevice on a capture shaft into a pericardial sac, wherein the capturedevice comprises a first jaw and a second jaw, wherein each of the firstjaw and the second jaw comprises an interior surface, wherein the firstjaw and the second jaw comprise an open configuration in which the firstjaw and the second jaw are open and a closed configuration in which thefirst jaw and the second jaw are closed, wherein the interior surface ofthe first jaw is located closer to the interior surface of the secondjaw when the first jaw and the second jaw are in the closedconfiguration than when the first jaw and the second jaw are in the openconfiguration, and wherein a first electrode is located on the internalsurface of the first jaw and a second electrode is located on theinternal surface of the second jaw; moving the first jaw and the secondjaw from the open configuration to the closed configuration afterdelivering the capture device into the pericardial sac, wherein movingthe first jaw and the second jaw captures a left atrial appendagebetween the first jaw and the second jaw; and confirming capture of theleft atrial appendage by the capture device by electrically stimulatingatrial tissue of the left atrial appendage using the first electrode onthe first jaw and the second electrode on the second jaw of the capturedevice after moving the first jaw and the second jaw from the openconfiguration to the closed configuration to capture the left atrialappendage and confirming that the atrial tissue is being paced; whereindelivering the capture device on the capture shaft into the pericardialsac comprises advancing the capture device over ventricular myocardiumtissue before the capture device reaches the left atrial appendage,detecting a capture shaft EGM signal using a capture shaft electrodelocated on the capture shaft proximal from the capture device, andconfirming that the capture shaft electrode is contacting ventriculartissue using the capture shaft EGM signal.
 19. A method of navigating adevice to the left atrial appendage according to claim 18, the methodfurther comprising detecting an EGM signal within the pericardial sacusing the first electrode of the capture device and confirming captureof the left atrial appendage by the capture device by determining if theEGM signal is associated with tissue of the left atrial appendage.
 20. Amethod of navigating a device to the left atrial appendage according toclaim 18, the method further comprising determining that the left atrialappendage is not captured between the first jaw and the second jaw ifthe EGM signal is not associated with tissue of the left atrialappendage.
 21. A method of navigating a device to the left atrialappendage according to claim 18, wherein the first jaw and the secondjaw comprise atraumatic nesting retention structure located at distalends of each of the first jaw and the second jaw, wherein proximal endsof each of the first jaw and the second jaw are located between thedistal ends of the first jaw and the second jaw and a distal end of thecapture shaft; wherein moving the first jaw and the second jaw to theclosed configuration comprises atraumatically capturing tissue in theatraumatic nesting retention structure.
 22. A method according to claim18, the method further comprising: injecting image enhancement liquidinto the pericardial sac; and wherein delivering the capture device intothe pericardial sac comprises advancing the capture device in thepericardial sac using a visual image obtained after injecting imageenhancement fluid into the pericardial sac.
 23. A method according toclaim 22, wherein the image enhancement fluid comprises a fluoroscopiccontrast agent and the visual image comprises a fluoroscopic image. 24.A method according to claim 18, wherein the capture device is deliveredto the pericardial sac in an approach that enters the pericardial sacthrough an opening formed in the pericardial sac and that does not passthrough the rib cage.
 25. A method of navigating a capture device to aleft atrial appendage, the method comprising: delivering a capturedevice on a capture shaft into a pericardial sac, wherein the capturedevice comprises a first jaw and a second jaw comprising an openconfiguration in which the first jaw and the second jaw are open and aclosed configuration in which the first jaw and the second jaw areclosed, wherein an interior surface of the first jaw is located closerto an interior surface of the second jaw when the first jaw and thesecond jaw are in the closed configuration than when the first jaw andthe second jaw are in the open configuration; moving the first jaw andthe second jaw from the open configuration to the closed configurationafter delivering the capture device into the pericardial sac, whereinmoving the first jaw and the second jaw captures the left atrialappendage between the first jaw and the second jaw; and confirmingcapture of the left atrial appendage by the capture device byelectrically stimulating atrial tissue of the left atrial appendageusing an electrode on the capture device after moving the first jaw andthe second jaw from the open configuration to the closed configurationto capture the left atrial appendage and confirming that the atrialtissue is being paced; wherein delivering the capture device on thecapture shaft into the pericardial sac comprises advancing the capturedevice over ventricular myocardium tissue before the capture devicereaches the left atrial appendage, detecting a capture shaft EGM signalusing a capture shaft electrode located on the capture shaft proximalfrom the capture device, and confirming that the capture shaft electrodeis contacting ventricular tissue using the capture shaft EGM signal. 26.A method according to claim 25, the method further comprising: detectingan electrical signal in the pericardial sac using an electrode on thecapture device after moving the first jaw and the second jaw from theopen configuration to the closed configuration; and confirming captureof the left atrial appendage by the capture device by determining if theelectrical signal is associated with electrical signals generated bytissue of the left atrial appendage.
 27. A method according to claim 26,wherein the electrode on the capture device comprises a first electrodeon the first jaw and a second electrode on the second jaw, and whereindetecting the electrical signal comprises detecting the electricalsignal using the first electrode and the second electrode.
 28. A methodaccording to claim 26, wherein the method further comprises determiningthat the left atrial appendage is not captured between the first jaw andthe second jaw if the electrical signal is not associated with tissue ofthe left atrial appendage.
 29. A method according to claim 25, whereinthe capture device comprises atraumatic nesting retention structure thatcomprises structure located at a distal end of the first jaw andstructure located at a distal end of the second jaw, wherein a proximalend of the first jaw is located between the distal end of the first jawand the distal end of the capture shaft, and wherein a proximal end ofthe second jaw is located between the distal end of the second jaw and adistal end of the capture shaft on which the capture device is carried;wherein moving the first jaw and the second jaw to the closedconfiguration comprises atraumatically capturing tissue in theatraumatic nesting retention structure.
 30. A method according to claim29, wherein the electrode on the capture device is located proximallyfrom the atraumatic nesting structure such that the atraumatic nestingretention structure does not form a part of the electrode.
 31. A methodaccording to claim 25, the method further comprising: injecting imageenhancement liquid into the pericardial sac; and wherein delivering thecapture device into the pericardial sac comprises advancing the capturedevice in the pericardial sac using a visual image obtained afterinjecting image enhancement fluid into the pericardial sac.
 32. A methodaccording to claim 31, wherein the image enhancement fluid comprises afluoroscopic contrast agent and the visual image comprises afluoroscopic image.
 33. A method according to claim 25, wherein thecapture device is delivered to the pericardial sac in an approach thatenters the pericardial sac through an opening formed in the pericardialsac and that does not pass through the rib cage.